Time and Work
MCQs Math


Question:     Jason can finish a work in 59 days. Ryan can finish the same work in 64 days while Jacob can finish the work in 69 days. How long will it take to finish it if they work together?


Correct Answer  21 3021/12263 days or 21.246 days

Solution And Explanation

Solution

Given,

The number of days required to finish a piece of work by Jason = 59 days

And, the number of days required to finish the same work by Ryan = 64 days

And, the number of days required to finish the same work by Jacob = 69 days

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

Here,

∵ In 59 days the work is done by Jason = 1

∴ The work done by Jason in 1 day = 1/59

Similarly,

∵ In 64 days the work is done by Ryan = 1

∴ The work done by Ryan in 1 day = 1/64

Similarly,

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

∴ The work done by Jacob in 1 day = 1/69 part

Now, the work done by Jason, Ryan, and Jacob together in 1 day

= Jason's 1 day work + Ryan's 1 day work + Jacob's 1 day work

= 1/59 + 1/64 + 1/69

= 4416 + 4071 + 3776/260544

= 12263/260544 part of work

This means in 1 day, 12263/260544 part of work is done by Jason, Ryan and Jacob working together.

Now, the number of days required to finish 12263/260544 part of work by Jason, Ryan, and Jacob working together = 1

∴ the number of days required to finish the whole work (1 work) by Jason + Ryan + Jacob together

= 1/12263/260544

= 1 × 260544/12263 = 260544/12263 days

= 21 3021/12263 days = or 21.246 days

Thus, Jason, Ryan, and Jacob working together will finish the total work (1 work) in 21 3021/12263 days = or 21.246 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 Jason = 59 days

And the number of days required to finish the same work by Ryan = 64 days

And the number of days required to finish the work by Jacob = 69 days

Thus, the number of days required to finish the work by Jason, Ryan, and Jacob together = ?

Here a = 59 days

And, b = 64 days

And, c = 69 days

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

The number of days required to finish the work when Jason, Ryan, and Jacob working together

= 59 × 64 × 69/59 × 64 + 59 × 69 + 64 × 69 days

= 260544/3776 + 4071 + 4416 days

= 260544/12263 days

= 260544/12263 days

= 21 3021/12263 days or 21.246

Thus, Jason, Ryan, and Jacob together will finish the work in 21 3021/12263 days or 21.246 days Answer


Similar Questions

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