Thursday, September 22, 2016

Time & Work (Part - 3)

WHEN GROUP WORK IS GIVEN & ASKED TO FIND INDIVIDUAL WORK

In these types of questions the time taken by a group of persons to complete a particular work is given and time taken by one individual also given. Then asked to find the time taken to complete the same work by the other individual.

How to solve these types of questions? Lets see.

As discussed in the previous post, we'll follow the same procedure with a little change.

This concept will be cleared by the following example.

Q: A and B can finish a piece of work in 6 days and A alone can do it in 9 days. The time taken by B alone to do the work is?

(A) 20 days
(B) 18 days
(C) 24 days
(D) 16 days
(E) None of these

Sol:     A + B ----- 6               3

                                     18

              A     ----- 9               2
                                         ---------
                                 Diff = 1 (3-2)

        Therefore,  B ----- 18/1 = 18 days
Hence, B alone can complete the work in 18 days.

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To master this concept do practice more number of similar problems.

Try this:

Q: A and B together can do a piece of work in 8 days. If A alone can do the same work in 12 days, then B alone can do the same work in?

(A) 20 days
(B) 16 days
(C) 24 days
(D) 28 days
(E) None of these

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Q: A can do a piece of work in 4 days. B can do it in 5 days. With the assistance of C they completed the work in 2 days. Find in how many days can C alone do it?

(A) 10 days
(B) 20 days
(C) 4 days
(D) 5 days
(E) None of these

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ALL THE BEST

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