View in English View in Hindi A and B together can do a work in 8 days. If A alone can do it in 12 days, then in how many days can B alone do it?
A और B एक साथ 8 दिनों में एक कार्य कर सकते हैं। यदि A अकेले इसे 12 दिनों में कर सकता है, तो B अकेले इसे कितने दिनों में कर सकता है?
A) 12 days
B) 20 days
C) 24 days
D) 28 days
Correct Answer : 24 days
Explanation : If X can do a piece of work in n days, then X's 1 day's work =1/n
If A and B, working together,and can complete a piece of work in X days. If A, working alone, can
complete the work in Y days, then B working alone, will complete the work in XY/(Y-X) days.
Then ,B alone can complete = (12 * 8) / (12 - 8) = 96/4 = 24 days
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A is twice as good as workman as B and therefore able to finish a piece of work in 30 days less than B. In how many days can they complete the whole work together?
A, B की तुलना में दोगुना बेहतर श्रमिक है और किसी कार्य को B से 30 दिनों से कम समय में पूरा करने में सक्षम है। कितने दिनों में वे एक साथ पूरे कार्य को समाप्त कर सकते हैं?
A) 20 days
B) 40 days
C) 60 days
D) 80 days
Correct Answer : 20 days
Explanation : Let A takes X days to complete the work and B takes 2X days
according to question, A takes 30 days less than B, that is X = 2X – 30
X=30
thus ,A take 30 days to complete the work and B takes 60 days
hence, A and B one days work is 1/30 + 1/60 = 1/20
Therefore, the whole job together they will be completed in 20 days
16 workers working 6 hours day can build a wall of length 150m, breadth 20m, and height 12m in 25 days. In how many days 12 workers, working 8 hours a day will build a wall of length 800m, breadth 15m and height 6m?
16 लोग 6 घंटे प्रतिदिन काम करके एक 150 मीटर लंबी, 20 मीटर चौड़ी और 12 मीटर ऊँची दीवार को 25 दिन में बना सकते हैं। 12 लोग 8 घंटें प्रतिदिन काम करके 800 मीटर लंबी 15 मीटर चौड़ी और 6 मीटर ऊँची दीवार कितने दिन में बना सकते हैं?
A) 50 days
B) 25 days
C) 25 days
D) 60 days
Correct Answer : 50 days
Explanation : to build a wall of 150*20*12=36000 ,hours required = 16*6*25=2400
to build a wall of 800*15*6=72000 , which is exactly twice as big as the first one,
You need 2400*2 hours = 4800
that is 12*8*days = 4800
days = 4800/96 = 50
A can do a piece of work in 10 days while B can do the same work in 20 days. They start together but A leaves after three days. How many days will B take to complete the remaining work?
A एक काम को 10 दिन में कर सकता हैं जबकि B उसी काम को 20 दिन में कर सकता है। वे दोनो एक साथ काम शुरू करते हैं, लेकिन 3 दिन बाद A काम छोड़ देता हैं। बचे हुए काम को करने में B को कितने दिन का समय लगेगा?
A) 14 days
B) 8 days
C) 12 days
D) 11 days
Correct Answer : 11 days
Explanation : One day's work of A and B = (1/10 + 1/20) = 3/20
Work done by A and B together in the 3 days = 3 (1/10 + 1/20) = 9/20
Remaining Work =1- 9/20 = 11/20
1/20 Work done by B in a day
thus,11/20 Work wll be done by B in (11/20)*20 =11 days
If 3 men or 4 women can reap a field in 30 days, how long will 3 men and 6 women take to reap it?
3 पुरूष या 4 महिलाएं एक खेत को 30 दिनों में काट सकते है, उसी खेत को काटने में 3 पुरूषों और 6 महिलाओं को कितना समय लगेगा?
A) 21 days
B) 16 days
C) 18 days
D) 12 days
Correct Answer : 12 days
Explanation : 3 men can complete work in 30 days
so, Work done by one man in a day = 1/(3*30)
and Work done by one women in a day =1/(4*30))
Thus, 3 men and 6 women will work in a day => 3/(3*30) + 6/(4*30)
= 1/30( 1 + 6/4)
= (1/30)*(10/4) =>1/12
3 men and 6 women do 1/12th part of work in a day,so they will complete the work in 12 days
A is twice as good a workman as B, and finishes the work in 14 days less than B. In how many days can it be done by A alone?
A, B से दोगुना बेहतर श्रमिक है, और किसी काम को B से 14 दिन पहले ख़त्म करता है, तो A अकेला उसी काम को कितने दिन में ख़त्म करेगा?
A) 14
B) 21
C) 28
D) 42
Correct Answer : 14
Explanation : let A take X days to complete the work and B takes 2X days
according to question, A takes 14 days less than B, that is X = 2X – 14 =>14
thus ,A take 14 days to complete the work and B takes 28 days.
30 persons can do a piece of work in 24 days. How many more people are required to complete the work in 20 days?
30 व्यक्ति एक काम को 24 दिनों में कर सकते है काम को 20 दिनों में पूर्ण करने हेतु कितने और व्यक्तियों की आवश्यकता है?
A) 4
B) 5
C) 6
D) 10
Correct Answer : 6
Explanation : let X persons required to complete the work in 20 days
then, work done => 30 * 24 = X *20
thus ,num of persons, X = 720 / 20 => 36
extra ,more people required = 36 - 30 = 6 persons
A is twice as good workman as B. Together, they finish the work in 14 days. In how many days can it be finish by B separately?
A, B से दो गुना अच्छा श्रमिक है । वे एक साथ एक कार्य को 14 दिन में समाप्त कर दे ते है । B को अकेले इस कार्य को समाप्त करने में कितने दिन का समय लगेगा?
A) 21
B) 48
C) 42
D) 35
Correct Answer : 42
Explanation : let A take X days to complete the work and B takes 2X days.
A's one day work = 1/X , B's one day work = 1/2X
(A+B)'s one day work => 1/X + 1/2X = 1/14
=> 14/X + 14/2X = 1
=> 14+7=X
=> X=21
Thus,
B working alone will require 2*21=42 days to complete the work
A working alone will require 21 days to complete the work
A can do a piece of work in 30 days while B can do it in 40 days. In how many days can A and B working together do it ?
A, 30 दिनों में एक कार्य कर सकता है जबकि B वह 40 दिनों में कर सकता है। कितने दिन A और B मिलकर यह कार्य कर सकते हैं?
A) 70 days
B) 171/4 days
C) 190/7 days
D) 120/7 days
Correct Answer : 120/7 days
Explanation : If X can do a piece of work in n days, then X's 1 day's work =1/n
Then (A + B)'s 1 day's work = (1/30 + 1/40) = 7/120
Hence, Time taken by both to finish the work = 120/7 days
A can do a piece of work in 20 days which B can do in 12 days. B worked at it for 9 days. A can finish the remaining work in ?
A एक कार्य 20 दिनों में कर सकता है जबकि B वह 12 दिनों में कर सकता है। B ने 9 दिनों तक कार्य किया। A शेष कार्य को कितने दिन में समाप्त कर सकता है?
A) 3 days
B) 5 days
C) 7 days
D) 11 days
Correct Answer : 5 days
Explanation : If X can do a piece of work in n days, then X's 1 day's work =1/n
B's 9 day's work = 9 * (1/12) = 3/4
Remaining work = (1 - 3/4) = 1/4
1/4 work is done by A in = 20 * (1/4) = 5 day
A can do a piece of work in 12 days. B is 60% more efficient than A. The number of days, it take B to do the same piece of work is ?
A एक कार्य 12 दिनों में कर सकता है। B, A की तुलना में 60% अधिक कुशल है। B को कार्य करने में कितना समय लगेगा ?
A) 15/2
B) 25/4
C) 8
D) 6
Correct Answer : 15/2
Explanation : A's 1 day's work = 1/12
B's 1 day's work = 1/12 + 60% of 1/12 = 1/12 x 160/100 = 2/15
Hence,B can do the work in 15/2 days
X is 4 times more efficient than Y, in what proportion will the number of days taken by X and Y to complete any work?
X, Y की तुलना में 4 गुना अधिक कुशल है, तो किसी कार्य को समाप्त करने के लिए X और Y द्वारा लिए गए दिनों की संख्या किस अनुपात में होगी?
A) 8 : 1
B) 1 : 5
C) 6 : 8
D) 5 : 1
Correct Answer : 1 : 5
Explanation : If A is twice as good a workman as B, then:
(a) Ratio of work done by A and B is 2:1.
(b) Ratio of times taken by by A and B to finish a work is 1:2.
Efficiency (X : Y) = 5 : 1
No. of days (X : Y) = 1 : 5
20 persons completed 1/3 rd of the work in 12 days. How many more person are required to finish the rest work in next 12 days?
20 व्यक्तियों ने 12 दिनों में एक कार्य का 1/3 भाग पूरा किया। अगले 12 दिनों में शेष कार्य पूरा करने के लिए कितने और लोगों की आवश्यकता है?
A) 20
B) 12
C) 18
D) 40
Correct Answer : 20
Explanation : Work done by 20 persons = 1/3
Remaining work = 1- 1/3 = 2/3
So for double work in same days we need double number of people i.e. 40.
Hence, 20 more people are needed.
6 children and 2 men complete a certain piece of work in six days. Each child takes twice the time taken by a man to finish the work. In how many days will 5 men finish the same work?
6 बच्चे और 2 पुरुष छह दिनों में एक निश्चित काम पूरा करते हैं। प्रत्येक बच्चा एक पुरुष द्वारा किए गए कार्य की तुलना में दो गुना अधिक समय लेता है। 5 पुरुष कितने दिनों में कार्य पूरा करेंगे?
A) 6
B) 8
C) 9
D) 15
Correct Answer : 6
Explanation : 6C + 2M = 6 days
36C + 12M = 1 day
As is given 1M = 2C
Then, 36C +12*2C = 1 day
60 children can work in 1 day
Now, 5 men = 10 children
Then, 10 children can work in 6 days.So 5 men also can complete the work in 6 days.
If 6 men and 8 boys can do a piece of work in 10 days while 26 men and 48 boys can do the same work in 2 days,then the time taken by 15 men and 20 boys in doing the same type of work will be?
यदि 6 आदमी और 8 लड़के दस दिनों में एक कार्य कर सकते हैं, जबकि 26 पुरुष और 48 लड़के 2 दिनों में वही कार्य कर सकते हैं, तो 15 पुरुषों और 20 लड़कों द्वारा उस कार्य को करने में लगने वाला समय क्या होगा?
A) 4
B) 6
C) 8
D) 9
Correct Answer : 4
Explanation : Let a man one day work is X and a boy one day work is Y. Then
6x + 8y =1/10
26x + 48y =1/2
After resolving above equations
x =1/100
y =1/200
15x + 20y = 15/100+20/200 = 1/4
Hence, 15 men and 20 boys to do that work in 4 days
6 men or 10 women can reap a field in 15 days, then the number of days that 12 men and 5 women will take to reap the same field is :
6 पुरुष या 10 महिलाएं 15 दिनों में एक खेत को काट सकती हैं, 12 पुरुषों और 5 महिलाओं को उसी खेत को काटने में कितने दिन लगेंगे?
A) 5
B) 6
C) 8
D) 12
Correct Answer : 6
Explanation : Work done by 6 men = work done by 10 women.
Work done by 1 man = work done by 10 / 6 women= 5/3 women
∴ 12 men + 5 women = 12 x ( 5 / 3) + 5 = 25 women
∴ W1 * D1 = W2 * D2 [W = women, D=days]
10 * 15 = 25 * D2
D2 = 6
A can do a work in 15 days and B in 20 days. If they work on it together for 4 days, then the fraction of the work that is left is?
A 15 दिनों में और B 20 दिनों में एक कार्य कर सकता है। यदि वे एक साथ 4 दिनों के लिए इस पर काम करते हैं, तो शेष कार्य क्या है?
A) 1/4
B) 4/10
C) 7/15
D) 8/15
Correct Answer : 8/15
Explanation : A's 1 day's work = 1/15
B's 1 day's work = 1/20
(A + B)'s 1 day's work = 1/15 + 1/20 = (4+3) / 60 = 7/60
(A + B)'s 4 day's work = (7/60) * 4 = 7/15
Therefore, Remaining work = 1 – (7/15) = 8/15