Answer: Option B
Explanation:
Ratio of times taken by Sakshi and Tanya = 125 : 100 = 5 : 4.
Suppose Tanya takes x days to do the work.
5 : 4 :: 20 : x x =   4 x 20  
5 
x = 16 days.
Hence, Tanya takes 16 days to complete the work.
21. 
A takes twice as much time as B or thrice as much time as C to finish a piece of work. Working together, they can finish the work in 2 days. B can do the work alone in:

Answer: Option B
Explanation:

22. 
A and B can complete a work in 15 days and 10 days respectively. They started doing the work together but after 2 days B had to leave and A alone completed the remaining work. The whole work was completed in :

Answer: Option C
Explanation:

23. 
A and B can do a piece of work in 30 days, while B and C can do the same work in 24 days and C and A in 20 days. They all work together for 10 days when B and C leave. How many days more will A take to finish the work?


24. 
A works twice as fast as B. If B can complete a work in 12 days independently, the number of days in which A and B can together finish the work in :

Answer: Option A
Explanation:
Ratio of rates of working of A and B = 2 : 1.
So, ratio of times taken = 1 : 2.
A's 1 day's work =  1  ; (2 times of B's work) 
6 
(A + B)'s 1 day's work =   1  +  1   =  3  =  1  . 
6  12  12  4 
So, A and B together can finish the work in 4 days.

25. 
Twenty women can do a work in sixteen days. Sixteen men can complete the same work in fifteen days. What is the ratio between the capacity of a man and a woman?

A.  3 : 4 
B.  4 : 3 
C.  5 : 3 
D.  Data inadequate 
Answer: Option B
Explanation:
(20 x 16) women can complete the work in 1 day.
1 woman's 1 day's work =  1  . 
320 
(16 x 15) men can complete the work in 1 day.
1 man's 1 day's work =  1 
240 
So, required ratio 



 = 4 : 3 (cross multiplied) 
26. 
A and B can do a work in 8 days, B and C can do the same work in 12 days. A, B and C together can finish it in 6 days. A and C together will do it in :

Answer: Option C
Explanation:

27. 
A can finish a work in 24 days, B in 9 days and C in 12 days. B and C start the work but are forced to leave after 3 days. The remaining work was done by A in:


28. 
X can do a piece of work in 40 days. He works at it for 8 days and then Y finished it in 16 days. How long will they together take to complete the work?


29. 
A and B can do a job together in 7 days. A is 1 times as efficient as B. The same job can be done by A alone in :

Answer: Option B
Explanation:

30. 
A and B together can do a piece of work in 30 days. A having worked for 16 days, B finishes the remaining work alone in 44 days. In how many days shall B finish the whole work alone?

Answer: Option C
Explanation:
Let A's 1 day's work = x and B's 1 day's work = y.
Then, x + y =  1  and 16x + 44y = 1. 
30 
Solving these two equations, we get: x =  1  and y =  1 
60  60 
B's 1 day's work =  1  . 
60 
Hence, B alone shall finish the whole work in 60 days.



No comments:
Post a Comment