Time and Work
MCQs Math


Question:     Steven can finish a work in 37 days. Andrew can finish the same work in 42 days while Joshua can finish the work in 47 days. How long will it take to finish it if they work together?


Correct Answer  13 4567/5267 days or 13.867 days

Solution And Explanation

Solution

Given,

The number of days required to finish a piece of work by Steven = 37 days

And, the number of days required to finish the same work by Andrew = 42 days

And, the number of days required to finish the same work by Joshua = 47 days

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

Here,

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

∴ The work done by Steven in 1 day = 1/37

Similarly,

∵ In 42 days the work is done by Andrew = 1

∴ The work done by Andrew in 1 day = 1/42

Similarly,

∵ In 47 days the work is done by Joshua = 1

∴ The work done by Joshua in 1 day = 1/47 part

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

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

= 1/37 + 1/42 + 1/47

= 1974 + 1739 + 1554/73038

= 5267/73038 part of work

This means in 1 day, 5267/73038 part of work is done by Steven, Andrew and Joshua working together.

Now, the number of days required to finish 5267/73038 part of work by Steven, Andrew, and Joshua working together = 1

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

= 1/5267/73038

= 1 × 73038/5267 = 73038/5267 days

= 13 4567/5267 days = or 13.867 days

Thus, Steven, Andrew, and Joshua working together will finish the total work (1 work) in 13 4567/5267 days = or 13.867 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 Steven = 37 days

And the number of days required to finish the same work by Andrew = 42 days

And the number of days required to finish the work by Joshua = 47 days

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

Here a = 37 days

And, b = 42 days

And, c = 47 days

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

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

= 37 × 42 × 47/37 × 42 + 37 × 47 + 42 × 47 days

= 73038/1554 + 1739 + 1974 days

= 73038/5267 days

= 73038/5267 days

= 13 4567/5267 days or 13.867

Thus, Steven, Andrew, and Joshua together will finish the work in 13 4567/5267 days or 13.867 days Answer


Similar Questions

(1) Thomas can finish a work in 17 days. Charles can finish the same work in 18 days while Christopher can finish the work in 19 days. How long will it take to finish it if they work together?

(2) Karen can finish a work in 20 days. Lisa can finish the same work in 21 days while Nancy can finish the work in 22 days. How long will it take to finish it if they work together?

(3) If Amanda can finish the work in 45 days and Patrick can finish the same work in 49 days, then in how many days both can finish the work together?

(4) If Anthony can finish the work in 31 days and Jeffrey can finish the same work in 36 days, then in how many days both can finish the work together?

(5) If Sharon can finish the work in 60 days and Zachary can finish the same work in 65 days, then in how many days both can finish the work together?

(6) Amanda can finish a work in 44 days. Dorothy can finish the same work in 45 days while Melissa can finish the work in 46 days. How long will it take to finish it if they work together?

(7) If Janet can finish the work in 98 days and Russell can finish the same work in 103 days, then in how many days both can finish the work together?

(8) John can finish a work in 5 days. Michael can finish the same work in 6 days while David can finish the work in 7 days. How long will it take to finish it if they work together?

(9) If Dorothy can finish the work in 47 days and Jack can finish the same work in 50 days, then in how many days both can finish the work together?

(10) If Christopher can finish the work in 22 days and Brian can finish the same work in 26 days, then in how many days both can finish the work together?


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