Time and Work
MCQs Math


Question:     Nicholas can finish a work in 69 days. Jonathan can finish the same work in 74 days while Stephen can finish the work in 79 days. How long will it take to finish it if they work together?


Correct Answer  24 9702/16403 days or 24.591 days

Solution And Explanation

Solution

Given,

The number of days required to finish a piece of work by Nicholas = 69 days

And, the number of days required to finish the same work by Jonathan = 74 days

And, the number of days required to finish the same work by Stephen = 79 days

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

Here,

∵ In 69 days the work is done by Nicholas = 1

∴ The work done by Nicholas in 1 day = 1/69

Similarly,

∵ In 74 days the work is done by Jonathan = 1

∴ The work done by Jonathan in 1 day = 1/74

Similarly,

∵ In 79 days the work is done by Stephen = 1

∴ The work done by Stephen in 1 day = 1/79 part

Now, the work done by Nicholas, Jonathan, and Stephen together in 1 day

= Nicholas's 1 day work + Jonathan's 1 day work + Stephen's 1 day work

= 1/69 + 1/74 + 1/79

= 5846 + 5451 + 5106/403374

= 16403/403374 part of work

This means in 1 day, 16403/403374 part of work is done by Nicholas, Jonathan and Stephen working together.

Now, the number of days required to finish 16403/403374 part of work by Nicholas, Jonathan, and Stephen working together = 1

∴ the number of days required to finish the whole work (1 work) by Nicholas + Jonathan + Stephen together

= 1/16403/403374

= 1 × 403374/16403 = 403374/16403 days

= 24 9702/16403 days = or 24.591 days

Thus, Nicholas, Jonathan, and Stephen working together will finish the total work (1 work) in 24 9702/16403 days = or 24.591 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 Nicholas = 69 days

And the number of days required to finish the same work by Jonathan = 74 days

And the number of days required to finish the work by Stephen = 79 days

Thus, the number of days required to finish the work by Nicholas, Jonathan, and Stephen together = ?

Here a = 69 days

And, b = 74 days

And, c = 79 days

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

The number of days required to finish the work when Nicholas, Jonathan, and Stephen working together

= 69 × 74 × 79/69 × 74 + 69 × 79 + 74 × 79 days

= 403374/5106 + 5451 + 5846 days

= 403374/16403 days

= 403374/16403 days

= 24 9702/16403 days or 24.591

Thus, Nicholas, Jonathan, and Stephen together will finish the work in 24 9702/16403 days or 24.591 days Answer


Similar Questions

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(2) If Amanda can finish the work in 45 days and Patrick can finish the same work in 48 days, then in how many days both can finish the work together?

(3) If Matthew can finish the work in 26 days and Edward can finish the same work in 30 days, then in how many days both can finish the work together?

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(6) If Brian can finish the work in 46 days and Raymond can finish the same work in 49 days, then in how many days both can finish the work together?

(7) If Margaret can finish the work in 32 days and Ryan can finish the same work in 37 days, then in how many days both can finish the work together?

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