SOURCE: Khairul’s Basic Math & Khairul’s Bank Math: ( †h †Kvb Z‡_¨i Rb¨: 01751-332407 ) # ব ব ব ব , ব ব
শ শ শ শ ব ব Khairul's Bank Math ব! ব! " " । #"$ %ব %ব ! ! %& %& ব' ব' #() #() *) % % #! ব!+ ব!+ " " ।
eB‡qi Z_¨¸‡jv GRb¨ Rvbvjvg hv‡Z hv‡`i cÖ ‡qvRb eB! "#$Ö % Ki‡Z cv‡ib: "e&i‡'i cÖ () "e‡_‡K "%R e¨v*¨vq "+ ,`iv‡e "vRv‡bv †$v.v‡bv cv‡eb/ [Janata Bank (EO)-20!(Afternoon)] (EO)-20! (Afternoon)] 1. The sum of two numbers is equal e qual to thrice their difference. If the smaller of the number is 10.find the other number [Janata Bank (EO)-2017 (aft ernoon)] a.15 b.20 c.40 d.None of these S"luti"n: (#) Let the larger number is x T!" x#10 $ %&x'10( %&x'10( or" x#10 $ %x'%0 or" '2x$'40 '2x$'40 so" x $ 20 ns) 20
2. The a*erage age of + men is increased b, 2 ,ears when one of them whose age is 24 ,ears is re-laced b, a woman. hat is the age of the woman [Janata Bank (EO)-2017 (afternoon)]
a.%5,ears
b.2+,ears
c.%2 ,ears
d.40,ears
S"luti"n: ($)
8 R‡bi eqm 2 eQi K‡i evo‡j †gv‡U evo‡e 8×2 = 16 eQi| A_© vr bZz b Avmv gwnjvwU P‡j v!qv 2" eQi eqm# †jv‡Ki †P‡q 16 eQi eo| m$ Ziv% gwnjvi eqm = 2"&16 = "' "' eQi| %. 50/ of a/ of b is 5/ of b/ of . hich hich of the following following is [Janata Bank (EO)2017 (afternoon)] (afternoon)]
a.1.5a
b.0.33a
c.0.5a
d.1.25a
S"luti"n: (#)
50/ of a/ of b $ b ×
50
×
a
$
ab
100 100 200 5 b %b × gain 5/ of b/ of $ × $ 100 100 400 ab %b %
Now"
200
$
400
or" a $
2
or % $ 2a or $
2a %
$ 0.33a
4. maes an article for T.120 and sells it to 6 at a -rofit of 25/ . 6 sells it to who sells it for T.175 maing a -rofit of 10/. hat -rofit -ercent did 6 mae [Janata Bank (EO)-2017 (afternoon)]
a.25/
b.20/
c.13.33/
d.15/
S"luti"n: (#) 8s s-$ 125/ of 120$150 68s s- is not gi*en but sell it it 17+ t which which mae 10/ -rofit 17+ × 100 so" 8s cost$ 110/ $ 17+" 1/ $ $1+0 110 finall, 6 -urchased it for 150 150 and sell it to 1+0t 9o" 6:s -rofit -ercent $ %0 × 100 = 20/ 150 5. sum of T.300 amounts to T.20 in 4 ,ears at sim-le interest. hat will it amount to if the rate of interest is increased b, 2/ [Janata Bank (EO)-2017 (afternoon)] a.T.34+ b.T.3+ c.T.23 d.T.72 S"luti"n: (#)
; ) 20'300$120 120<4$%0 -er ,ear interest %0=100<300$5/ -er ,ear rate of interest after increasing" it will sha-e &5#2($/ 300=/=4$13+ total$300#13+$3+
2/ & 2/ ( g+ ‡* g+ ‡* "gv&vb Kivi Rb¨ Gv‡e ve+ b:
g+ ‡* g+ ‡* "gv&vb Kivi Rb¨ Gv‡e ve+ b: (KeQ‡i 1'' UvKv‡Z 2 UvKv AwZwi) †*‡j 6'' UvKv‡Z AwZwi) *v‡e 6×2 = 12 UvKv+ (e% " eQ‡i AwZwi) *v‡e 12×" = "8 UvKv| m$ Ziv% bZz b m$ ,vmj n‡e -2'&"8 = -68UvKv| 3. The sum of first fi*e -rime number is ) [Janata Bank (EO)-2017 (afternoon)]
a.11
b.1+
c.23
d.2+
S"luti"n: ($)
*._g _g /wU †g0wjK m%v n‡jv+ 2+ 3+ /+ -(e% 11 m$ Ziv% (‡,i †v45j = 2&3&/&-&11 = 28 28 3
. hat is the following is equal to %.14> 10 [Janata Bank (EO)-2017 (afternoon)] a.%14 b.%140 c.%140000 d.None of these S"luti"n: (c) %.14×103 %14 $ × 1000000 $ %14×10000 $%140000&ns( $%140000&ns( 100
+. If x$1 ' q and , $ 2q#1 " then for what what *alue of q. x is equal to , [Janata Bank (EO)-2017 (afternoon)]
a.'1
b.0
c.0.5
d.2
S"luti"n: (#)
‡‡nZz x $ , evbv‡Z n‡e| Zvn‡j †jv vq+ 1 ? q $ 2q#1 or" '%q $ 0 9o" q $ 0 &ans( Avevi A*b 7‡i! *. gv Kiv vq q $ o emv‡j x (e% , 9:‡qi gvb; mgvb nq| 7. If , $5 " then what is thr *alue of 10, a.50 2
b.100
, % − , 2 [Janata Bank (EO)-2017 (afternoon)] c.200 5
d.500
S"luti"n: ($)
‡‡nZz , $ 5 m$ Ziv% 10, , % − , 2 $ 10.5 5 % − 5 2 $ 50 125 − 25 $ 50 100 $50×10$500 10. % ,ears ago " the a*erage age a ge of a famil, of 5 members was 1 ,ears . bab, ha*ing been born " the a*erage age of the famil, is the same toda,. The -resent age of the bab, is ) [Janata Bank (EO)-2017 (afternoon)]
a.1,ear
b.1,ear 3months
c.2,ears
d.%,ears
S"luti"n: (c)
3 eQi Av‡4 /R‡bi eq‡mi 4o 11- eQi n‡j eZ© gvb 4o 1-&3 = 2' (e% eZ© gv‡b †gvU eqm = 2'×/ = 1'' Avevi bZz b (KRb †v4 †,qvq 6 R‡bi eZ© gvb 4o 1- (e% †gvU eqm eqm = 1-×6 = 1'2 m$ Ziv% w
11. There are two numbers such that the sum of twice the first and thrice t hrice the second is %7" while the sum of thrice the first and twice the second is %3. The largest of the two is ) [Janata Bank (EO)-2017 (afternoon)]
a.3
b.+
c.7
d.12
S"luti"n: (c) Let" the first number is x and second number is , @or first condition" 2x#%, $ %7 and for 2 nd condition %x#2, $ %3 6, sol*ing the equation we get x $ 3 and , $ 7" 9o" l argest number is 7 12. -erson was ased to state his age in ,ears .Ais re-l, was " Bt ae m, age three ,ears hence " multi-le is b, % and then subtract three ti mes m, age three ,ears ago and ,ou will now how old I am C hat was the age of -erson -erson [Janata Bank (EO)-2017 (afternoon)] a.1+,ears b.20,ears c.24,ears d.%2,ears
S"luti"n: (a)
eZ© gvb eqm K n‡j 3 eQi *‡i K&3 K&3 (e% 3w,‡q > Ki‡j n‡e 3?K&3@ Avevi (; eqm †_‡K we‡qv4 Ki‡Z n‡e wZbeQi Av‡4i eqm K 3 (i 3> = 3?K3@ 3?K3@ Zvn‡j eZ© gvb eqm *v!qv v‡e| *. g‡Z+ g‡Z+ 3?K&3@ 3?K3@ = K ev+ 3K&B 3K &B = K m$ Ziv% K = 18 A_v©r †jvKwUi eqm 18 eQi|
1%. If 2 n $ 34 " the then n the the *alu *aluee of of n is ) [Janata Bank (EO)-2017 (afternoon)] a.2 b.4 c.3 d.12
S"luti"n: ($) 2 n $ 34 34 or"
2 n $ 23 or" 2n $ 212 9o" n$12
14. In an election" %0/ of the *oters *oted for candidate whereas 30/ of the remaining *oted for candidate 6 . The remaining remaini ng *oters did not *ote. If the difference between those who *oted for candidate and those who did not *ote was 1200" how man, indi*iduals were eligible for casting *ote in the election [Janata Bank (EO)-2017 (afternoon)] a.10"000 b.45"000 c.30"000 d.2"000
S"luti"n: (c) andidate got $ %0/ 9o" Demaining $ 100'%0 $0/ andidate 6 got $ 30/ of 0 $ 42/ 9E" *oters did not *ote $ 0'42 $ 2+/ Fifference of and did not *ote is %0'2+ $ 2/ Now 2/ $ 1200 then 1/ $ 300 9E" 100/ $ 30"000 15. sho-ee-er ex-ects a gain of 22.5/ on his cost -rice . If in a wee his sale was of T.%72 " what was his -rofit [Janata Bank (EO)-2017 (afternoon)] a.T.1+.20 b.T.0 c.T.2 d.T.++.25
S"luti"n: (c) G $ 100/ and gain $ 22.5/ %72 %72 × 22.5 9o" 122.5/ $ %72 so" 1/ $ " Then" -rofit 22.5/ $ = 2 122 .5 122 .5 13. The least whole number which when subtracted from both the t erms of the ratio 3) gi*es a ratio less then 13)21 is ) [Janata Bank (EO)-2017 (afternoon)] a.2 b.% c.4 d.3
S"luti"n: (#) E-tion test or" or,6-x:7-x = 16:21 x= x= 14/5 x =3 16:21 " ! ! 16:21
1. 10 men woring 3 hours a da, can com-lete a wee in 1+ da,s .how man, hours a da, must 15 men wor to com-lete the same wor in 12 da,s [Janata Bank (EO)-2017 (afternoon)] a.3 b.10 c.12 d.15
S"luti"n: (a)
1'Rb 18 w,‡b Ki‡Z jv‡4 6 CDUv| Zvn‡j 1 Rb‡K †ew mgq (e% 1w,‡b Ki‡j Av‡iv †ew mgq jv4‡e A_© vr 6×1'×18 (b 1/Rb gvb$ E 12 w,‡b A_© vr †jvK (e% w,b Kgvi Kvi‡ w, > nq Zvn‡j evovi Kvi‡ :v4 n‡e n‡e Zv; 9Fi ? 6G1'G18@H?1/G12@ 6G1'G18@H?1/G12@ = 6CDUv| 1+. Two ta-s and 6 can fill a tan in 5 hours and 20 hours res-ecti*el, . If both the ta-s are o-en then due to leaage " it too %0 minutes more to fill the tan . If the tan is full " how long will it tae for the leaage alone to em-t, the tan [Janata Bank (EO)-2017 (afternoon)]
a.4.5hrs
b.hrs
c.1+hrs
d.%3hrs
S"luti"n: ($) #6 $ 1<5#1<20 $ 1<4 or 4 hours. Fue to leaage time t aen 4.5 hours 9o" Gower of the leaage is i s $ &4=4.5(< 4.5'4 $ 1+<.5 $ %3hrs 17. train can tra*el 50/ faster than a car. 6oth start from -oint at the same time and reach -oint 6 5ms awa, from at the same time . En the wa, " howe*er " the train lost about 12.5 minutes while sto--ing at the station . The s-eed of the car is ) [Janata Bank (EO)-2017 (afternoon)]
a.100m-h
b.110m-h
c.120m-h
d.1%0m-h
S"luti"n: (c) 9-eed ratio of Train and ar $ %)2 9o" Time ratio of train and car $ 2)% their time difference is %'2 $ 1 -art $ 12.5 min so ar taen %=12.5 $ %.5min 9o" 9-eed of the car i n 1 min is 5<%.5 $ 2m and i n 30min or 1 hour is 2=<30 $ 120m
20. towel " when balanced as found to ha*e lost 20/ of it s length and 10/ of ts breadth . The -ercen -ercentage tage of decr decreas eas in area is ) [Janata Bank (EO)-2017 (afternoon)] a.10/ b.10.0+/ c.20/ d.2+/
S"luti"n: ($)
*._‡g _‡g 2'I K‡g 8' nq| (i*i 8' (i 1'I A_© vr 8 K‡g| Zvn‡j †gv‡U Kg‡jv 2'&8 = 28I 28I|
[Janata Bank (EO)-20! (M"rnin%) ' @ind the greatest number that will di*ide 4%" 71 " and 1+% so as to lea*e the same remainder in each case. [Janata Bank (EO)-2017 (Morning)] a. b.7 c.% d.4
S"luti"n: ($)
(v‡b "3+ B1 (e% 183 †K (gb (KwU m%v w,‡q :v4 Ki‡Z n‡e v‡Z *. wZevi (K; :v4‡E _v‡K| A*b †_‡K *. wZwU m%v †_‡K " w,‡q :v4 Ki‡Z ‡4‡j "3+ B1 (e% 183 †K :v4 Kivi mgq *.* wZevi . 3 AewJ _v‡K| Zv; 9Fi "| i n*ested amount in the ratio 2)1 " whereas the ratio between 2' In a business " and in*ested amounts in*ested b, and 6 was %)2 . If T.1"5"%00 was their -rofit " how much amount did 6 recei*e [Janata Bank (EO)-2017 (Morning)] a.T.24"200 b.T.%3"%00 c.T.2"300 d.T.4+"400
S"luti"n: (#) In*est of and $ 2)1 or 3)% in*est of and 6 $%)2 of 3)4 9o" In*est of )6) $ 3)%)4 Now" total -rofit $ 15%00 % 9o 6" recei*ed $ 15%00 × $ %3%00 1% ' hich one of the following is not -rime number [Janata Bank (EO)-2017 (Morning)] a.%1 b.31 c.71 d.1
S"luti"n: (#) Aere all the numbers are -rime exce-t 71" 6ecause 71 $ 1% × ' &0.04( a.25
'1.5
$ [Janata Bank (EO)-2017 (Morning)] b.250
c.125
d.325
S"luti"n: (#) &0.04(
'1.5
$ &.2(
2&'1.5(
2 $ &.2( $ 10 '%
−%
%
10 1000 = = = 125 + 2
*' sum of mone, is borrowed and -aid bac in t wo annual installments of T.++2 each allowing 5/ com-ound interest . The sum borrowed was ) [Janata Bank (EO)-2017 (Morning)]
a.T.1320
S"luti"n: (c)
b.T.13+0
c.T.1340
d.T.100
evrmwiK 882 UvKv K‡i 2 eQi wKwLM w,‡j w,‡j †gvU m$ ,vmj 882&882 = 1-6" UvKv| (v‡b PNeO w m$ ‡,i nvi /I (e% mgq ,$ eQi| eQi| wK ,$ ,$ eQi (Kmv‡_ wn‡me Kiv v‡e bv| Kvi *._g _g eQ‡ii *. ,F wKwLM ‡Z 1 eQ‡ii m$ ,v $ ) n‡q‡Q wK wSZ#q wSZ#q eQ‡ii wKwLM ‡Z ,$ eQ‡ii eQ‡ii m$ , $ ) n‡q‡Q| Zv; *._g _g wKwLM vi Avmj 7wi+ x UvKv| *. g‡Z+ x (i 1'/I = 882 ev + , 2
1'' $ 8"' UvKv| 1'/
Avevi+ wSZ#q eQ‡ii *. ,F wKwLM ‡Z Avmj x 7i‡j+ *. g‡Z+ g‡Z+ x (i 1'/I (i 1'/I 1'/I = 882 ev+ + , 2
1'' 1'' 2' 2' $ 882× × $8'' 1'/ 1'/ 21 21
m$ Ziv% me© ‡gvU g$ j7b = 8"'&8'' = 16"'UvKv| 16"'UvKv| ' hat is the unit digit in the -roduct &3+4>57>41%>33( [Janata Bank (EO)-2017 (Morning)]
a.4
b.12
c.+
d.13
S"luti"n: (c)
<7$ †‡Ei †‡Ei wTwRU >‡jv > K‡i *v; 4×7 $ %3 (i*i %3 (i 3×% $ 1+ (i*i 1+ (i + (i mv‡_ +×3 $ 4+ Zvn‡j me>‡jv m%vi >5jwU Z eo; †nvK bv †Kb †‡E 8 _vK‡e| 9Fi 9Fi +| !' certain number of men can finish fi nish a -iece of wor in 100 da,s . If " there were 10 men less l ess " it would tae 10 da,s more for the wor to be fi nished. Aow man, men were there originall, [Janata Bank (EO)-2017 (Morning)] a.5 b.+2 c.110 d.100
♦S"luti"n: (c) Eriginall, let there be x men. Then x man need $100da,s ∴1
./ 1
100x x − 10
H: H:
$ 100x da,s
x'10 H: H:
$
100x x − 10
da,s
$110 or 100x $ 110x'1100 or 10x $ 1100 ∴x$110
' Ene ,ear ago " Gin, was four ti mes as old as her daughter 9oma. 9ix ,ears hence " -in,:s age will exceed her daughter:s age b, 7 ,ears. ,ears. The ratio of the -resent age of Gin, and her daughter is ) [Janata Bank (EO)-2017 (Morning)] a.7)2 b.11)% c.1%)4 d.12)5
♦S"luti"n: (c)
Let" one ,ear ago" 9oma was x ,ears and Gin, was 4x ,ears old Their -resent age is x#1 and 4x#1 and ages after 3 ,ears will be $ x# and 4x# ./1 x#$4x#'7 or" '%x $ '7 9o" x $ %
9o" age of soma was % and Gin, was 4 ×% $ 12 Datio of their -resent age is 12#1)%#1 $ 1%)4 3' The ratio between the -erimeter and the breadth of rectangle is 5)1 . If the area of rectangle is 213sq. cm " what is the length of the rectangle ?AvqZ‡‡Vi *wim#gv ! *. ‡LW i Ab$*vZ *vZ / 1|
AvqZ‡‡Vi †V5j 216 e4© ‡mXwgX ‡mXwgX n‡j Y,C© KZ@ a.13cm
b.24cm
[Janata Bank (EO)-2017 (Morning)]
c.20cm
d.1+cm
♦S"luti"n: ($) Let the -erimeter is $ 5x and the breadth is $ x 5x 5x − 2x %x − x $ 9o" the length is $ 2 2 2 Now the area is
%x 2
× x $
%x 2 2
./
%x 2 2
$ 213 ⇒%x2$ 4%2
⇒x2 $ 144
∴x$12 9o length is
0' &+>+#31>31'2>+>31( &+>+#31>31'2>+>31( $ [Janata Bank (EO)-2017 (Morning)] a.17+ b.173 c.273
% × 12 2
$1+cm
d.27+
♦S"luti"n: (n"n4) Let + $ a and 31 $ b 9o" a×a#b× b '2×a× b Er" a2#b2'2ab Er &a'b(2 now -utting the alue of a and b 2 2 &+'31( $ 23 $ 33 ' is faster then 6. and 6 each wal 24m. The sum of their s-eeds is m
a.% m
b.5 m
c.4 m
S"luti"n:(c) Let the s-eed of $ xm
d. m
T!"
24
+
24
$14 x −x 6," 9ol*ing the equation we get x $ 4 or % 9ince is @aster 9o :s 9-eed x $ 4m
g+ ‡* g+ ‡* "gv&vb Kivi Rb¨ Gv‡e ve+ b: (v‡b 4wZ‡e‡4i †‡V K6 Avevi Zv‡,i 4wZ‡e‡4i †v45j †‡nZz - Zvn‡j "&3 A_ev /&2 A_ev 6&1 n‡Z *v‡i| (b ,$ R‡b †‡nZz 2" 2" wKwg ‡n[ ‡U‡Q Zvn‡j jwRKvwj (gb m%v wb‡Z n‡e v w,‡q 2" 2" †K :v4 Kiv vq| (e% mgq ,$ wUi †v45j 1" CDUv nq| (b (i 4wZ‡e4 " (e% 6 (i 4wZ‡e4 3 7i‡j ‡K mgq jv4‡e 2"÷" = 6 CDUv (e% 6 ‡K mgq jv4‡e 2"÷ 3 = 8 CDUv| Zvn‡j ,$ Rb‡K †gvU mgq jv4‡jv jv4‡jv 8&6 = 1" CDUv| *. ‡ i mv‡_ wg‡j v!qvq 9Fi (i 4wZ‡e4 "wKwgHCDUv| Si5ilar 6u4sti"n: 1. ae is faster than Gaul. ae and Gaul each wal 40 m. The sum of their s-eeds is 1% m
a.22
b.24
c.4+
d.44
S"luti"n:($) In 12 hours" the hands coincide or are i n o--osite direction 22 times. In 24 hours" the hands coincide or are i n o--osite direction 44 times a da,. ' The sum of two numbers is 40 and their difference is 4. The ratio of numbers is ) [Janata Bank (EO)-2017 (Morning)]
a.22)7
b.11)7
c.11)1+
S"luti"n:(#) Let first number is m and second number is n. Then m # n $ 40 ''''''''M1 nd m ?n $ 4 ''''''''''M2 dding eq. 1 and eq. 2 e get" 2m $ 44 ⇒ m $ 22 Gutting *alue of m in eq. &1(" we get n $ 1+ ⇒m ) n $ 22 ) 1+ ∴m ) n $ 11 ) 7
d.21)17
, - - . . #( #( - - 1 7, 2 ! ! $% & %' & %' 2 2 " $%! & ( $%! & %' 2 ) &40#4(<2 $ 22 " $% &40'4(<2 &40'4(<2 $ 1+ * $ $ $ $ ) ( $% &40#4(<2 11 ) 7 ) 22 ) 1+ 11
' Two trains are running in o--osite directi ons with the same s-eed. If the l ength of each train is 120 meters and the, cross each ot her in 12 second " then the s-eed of e ach train &in h
S"luti"n:($) Let"the s-eed of each train be x m-h. 9o"relati*e s-eed$x#x$2x Length $D9 × &5<1+( 9ec $K &120#120($2s=&5<1+(=12 &120#120($2s=&5<1+(=12 $K240$29×&5<1+(=12 $K29$2 $K9$2<2 $%3&ns(
"%R v‡e Kivi Rb¨ Gv‡e ve+ b: ‡U\ b ,$ wUi ],‡C© i †v45j 12'&12' = 2"'wgUvi 2"'wgUvi vq 12 ‡m‡K‡^| Zvn‡j *. wZ †m‡K‡^i 4wZ‡e4 2"'÷12 = 2'wgH‡mX (b 1 †m‡K‡^ 2'wg+ †4‡j 36'' †m‡K‡^ vq 2'× 36'' = -2'''wgUvi ev -2wKwg| (b ,$ wU †U\ b we*i#Z w,K †_‡K Avmvq (e% Zv‡,i 4wZ‡e4 mgvb n!qvq †U\ b ,$ wUi *. ‡ZKwUi 4wZ‡e4 n‡e -2÷2 = 36wKwgH CDUv| *' The a*erage of first 50 natural numbers is ) [Janata Bank (EO)-2017 (Morning)] a.12.25
b.21.25
c.25.5
d.25
S"luti"n:(c) Natural number
wbqg n‡jv *._g *, ! †E*, †v4 K‡i 2w,‡q :v4 Ki‡Z n‡e| Zv; Zv; 4o /'&1 = /1÷2 = 2/X/| ' In an election a ca ndidate who gets +4/ of the *otes is e lected b, a maOorit, of 43 *otes. hat is the total number of *otes -olled & (KwU wbe© vP‡b (KRb *. v_© # 8"I †:vU ‡*‡q "-6 wU AwZwi) †:v‡U wbe© vwPZ nj| †gvU †:v‡Ui *wigv KZ@ [Janata Bank (EO)-2017 (Morning)] (BB AD) a.32 b.47 c.00 d.+4+
S"luti"n:(#) Total *ote $ 100/ innig candidate got $ +4/ 9o" other candidate got $ 100'+4 $ 13/ Fifference in / is $ +4/ ' 13/ $ 3+/ Fifference in *otes is $ 43 9o" 3+/ $ 43 ∴1/ $
43 3+
9o" 100/ $
43 × 100 3+
$ 00
!' The square root of & + % 5( & ' % 5 ( is ) [Janata Bank (EO)-2017 (Morning)]
a.
5
b.4
d. % 5
c.2
♦S"luti"n: (c)
( )
2
2 is & + % 5( & ' % 5 ( $ ' % 5 $47'45 $ 4 9o" 9quare root is
4 = 2 ns)
' sum of mone, lent out at sim-le interest amount to T.20 after 2 ,ears and to T.1020 after a further -eriod of 5 ,ears . The sum is ) [Janata Bank (EO)-2017 (Morning)] a.T.300 b.T.500 c.T.00 d.T.10
♦S"luti"n: (c) Grinci-al # 9I for 2 ,ears $20 T. ......&I( Grinci-al # 9I for ,ears $ 1020 T. ......&II( 9ubtracting equation &I( from &II(" 9.I. for 5 ,ears $ &1020 ?20( $ %00 T ∴9.I. for 1 ,ear is %00÷5 $ 30T and for 2 ,ears $ 30 ×2 $ 120T.P ∴Grinci-al $ &20 ' 120( $ 300 T 3' In a certain store " the -rofit is %20/ of the cost . If the cost increased b, 25/ but" the selling -rice remains constant " a--roximatel, what -ercentage of the selling -rice is the -rofit [Janata Bank (EO)-2017 (Morning)] a.%0/ b.100/ c.250/ d.0/
♦S"luti"n: ($) Let .G.$ T. 100. Then" Grofit $ T. %20" 9.G. $ T. 420. New .G. $ 125/ of T. 100 $ T. 125 New 9.G. $ T.. 420. 9o" Grofit $ T. &420 '125( $ T. 275. 275 × 100 Dequired -ercentage $ = 0/ &a--roximatel,( 420 20' 1%+.007#%41.7+1'143.%05$12%.3# [Janata Bank (EO)-2017 (Morning)] a.120.+5 b.120.0+5 c.220.0+5 d.None of these
♦S"luti"n: ($) Let 1%+.007 # %41.7+1 '143.%05 $ 12%.3 # Q Then" Q $ &1%+.07#%41.7+1( '&143.%05#12%.3($ '&143.%05#12%.3($ 47.77 '237.705 $ 210.0+5
$'Z b‡q †h †Kvb civg‡(i Rb¨ ‡"e+ ‡K †hv$v‡hv$ Kib _ev R‡qb Kib vgvi †"e+ K $Ö c : Khairul’s Basic Math
