Time and Work
MCQs Math


Question:     Paul can finish a work in 35 days. Andrew can finish the same work in 36 days while Joshua can finish the work in 37 days. How long will it take to finish it if they work together?


Correct Answer  11 3863/3887 days or 11.994 days

Solution And Explanation

Solution

Given,

The number of days required to finish a piece of work by Paul = 35 days

And, the number of days required to finish the same work by Andrew = 36 days

And, the number of days required to finish the same work by Joshua = 37 days

Thus, the number of days required to finish the work by all of them if they work together = ?

Here,

∵ In 35 days the work is done by Paul = 1

∴ The work done by Paul in 1 day = 1/35

Similarly,

∵ In 36 days the work is done by Andrew = 1

∴ The work done by Andrew in 1 day = 1/36

Similarly,

∵ In 37 days the work is done by Joshua = 1

∴ The work done by Joshua in 1 day = 1/37 part

Now, the work done by Paul, Andrew, and Joshua together in 1 day

= Paul's 1 day work + Andrew's 1 day work + Joshua's 1 day work

= 1/35 + 1/36 + 1/37

= 1332 + 1295 + 1260/46620

= 3887/46620 part of work

This means in 1 day, 3887/46620 part of work is done by Paul, Andrew and Joshua working together.

Now, the number of days required to finish 3887/46620 part of work by Paul, Andrew, and Joshua working together = 1

∴ the number of days required to finish the whole work (1 work) by Paul + Andrew + Joshua together

= 1/3887/46620

= 1 × 46620/3887 = 46620/3887 days

= 11 3863/3887 days = or 11.994 days

Thus, Paul, Andrew, and Joshua working together will finish the total work (1 work) in 11 3863/3887 days = or 11.994 days Answer

Shortcut Trick to solve the problems based on time and work using formula

Case: If A can finish a work in a days, B can finish the same work in b days, and C can finish the work in c days
then working together the number of days required to finish the work
= a × b × c/ab + ac + bc days.

Here given,

The number of days required to finish the work by Paul = 35 days

And the number of days required to finish the same work by Andrew = 36 days

And the number of days required to finish the work by Joshua = 37 days

Thus, the number of days required to finish the work by Paul, Andrew, and Joshua together = ?

Here a = 35 days

And, b = 36 days

And, c = 37 days

Thus, using formula a × b × c/ab + ac + bc days

The number of days required to finish the work when Paul, Andrew, and Joshua working together

= 35 × 36 × 37/35 × 36 + 35 × 37 + 36 × 37 days

= 46620/1260 + 1295 + 1332 days

= 46620/3887 days

= 46620/3887 days

= 11 3863/3887 days or 11.994

Thus, Paul, Andrew, and Joshua together will finish the work in 11 3863/3887 days or 11.994 days Answer


Similar Questions

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(2) If Larry can finish the work in 77 days and Lawrence can finish the same work in 82 days, then in how many days both can finish the work together?

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(6) Brenda can finish a work in 76 days. Emma can finish the same work in 81 days while Nicole can finish the work in 86 days. How long will it take to finish it if they work together?

(7) If Paul can finish the work in 36 days and Larry can finish the same work in 39 days, then in how many days both can finish the work together?

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