Aptitude - Time and Work - Discussion

Discussion Forum : Time and Work - General Questions (Q.No. 23)
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?
18 days
24 days
30 days
36 days
Answer: Option
Explanation:

2(A + B + C)'s 1 day's work = ( 1 + 1 + 1 ) = 15 = 1 .
30 24 20 120 8

Therefore, (A + B + C)'s 1 day's work = 1 = 1 .
2 x 8 16

Work done by A, B, C in 10 days = 10 = 5 .
16 8

Remaining work = ( 1 - 5 ) = 3 .
8 8

A's 1 day's work = ( 1 - 1 ) = 1 .
16 24 48

Now, 1 work is done by A in 1 day.
48

So, 3 work will be done by A in ( 48 x 3 ) = 18 days.
8 8

Discussion:
61 comments Page 7 of 7.

Vinoth said:   9 years ago
From the very first statement, we can calculate,

A's one day work as 1/60 i.e. (1/30) *(1/2). But they have done some confused calculations and saying that A's 1-day work is 1/48 this is not possible.

The ANSWER IS 22 + 1/2 days.

You all just check it by putting (10days A + B + C work ) + (22 + 1/2 days A's work alone) = 1. Then, you will get 1 which is the total work done


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