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 Shirley can finish the work in 72 days and Harold can finish the same work in 77 days, then in how many days both can finish the work together?

(3) If Elizabeth can finish the work in 33 days and Daniel can finish the same work in 49 days, then in how many days both can finish the work together?

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(6) John can finish a work in 9 days. David can finish the same work in 14 days while William can finish the work in 19 days. How long will it take to finish it if they work together?

(7) Shirley can finish a work in 72 days. Brenda can finish the same work in 77 days while Pamela can finish the work in 82 days. How long will it take to finish it if they work together?

(8) If David can finish the work in 10 days and Christopher can finish the same work in 14 days, then in how many days both can finish the work together?

(9) Elizabeth can finish a work in 14 days. Susan can finish the same work in 19 days while Jessica can finish the work in 24 days. How long will it take to finish it if they work together?

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