Time and Work
MCQs Math


Question:     Ashley can finish a work in 36 days. Emily can finish the same work in 41 days while Donna can finish the work in 46 days. How long will it take to finish it if they work together?


Correct Answer  13 1331/2509 days or 13.53 days

Solution And Explanation

Solution

Given,

The number of days required to finish a piece of work by Ashley = 36 days

And, the number of days required to finish the same work by Emily = 41 days

And, the number of days required to finish the same work by Donna = 46 days

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

Here,

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

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

Similarly,

∵ In 41 days the work is done by Emily = 1

∴ The work done by Emily in 1 day = 1/41

Similarly,

∵ In 46 days the work is done by Donna = 1

∴ The work done by Donna in 1 day = 1/46 part

Now, the work done by Ashley, Emily, and Donna together in 1 day

= Ashley's 1 day work + Emily's 1 day work + Donna's 1 day work

= 1/36 + 1/41 + 1/46

= 943 + 828 + 738/33948

= 2509/33948 part of work

This means in 1 day, 2509/33948 part of work is done by Ashley, Emily and Donna working together.

Now, the number of days required to finish 2509/33948 part of work by Ashley, Emily, and Donna working together = 1

∴ the number of days required to finish the whole work (1 work) by Ashley + Emily + Donna together

= 1/2509/33948

= 1 × 33948/2509 = 33948/2509 days

= 13 1331/2509 days = or 13.53 days

Thus, Ashley, Emily, and Donna working together will finish the total work (1 work) in 13 1331/2509 days = or 13.53 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 Ashley = 36 days

And the number of days required to finish the same work by Emily = 41 days

And the number of days required to finish the work by Donna = 46 days

Thus, the number of days required to finish the work by Ashley, Emily, and Donna together = ?

Here a = 36 days

And, b = 41 days

And, c = 46 days

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

The number of days required to finish the work when Ashley, Emily, and Donna working together

= 36 × 41 × 46/36 × 41 + 36 × 46 + 41 × 46 days

= 67896/1476 + 1656 + 1886 days

= 67896/5018 days

= 67896/5018 days

= 67896 ÷ 2/5018 ÷ 2 = 33948/2509 days

= 13 1331/2509 days or 13.53

Thus, Ashley, Emily, and Donna together will finish the work in 13 1331/2509 days or 13.53 days Answer


Similar Questions

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(2) If Nicholas can finish the work in 69 days and Roger can finish the same work in 74 days, then in how many days both can finish the work together?

(3) If Richard can finish the work in 14 days and Mark can finish the same work in 17 days, then in how many days both can finish the work together?

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(6) Daniel can finish a work in 23 days. Matthew can finish the same work in 24 days while Anthony can finish the work in 25 days. How long will it take to finish it if they work together?

(7) If Linda can finish the work in 31 days and Charles can finish the same work in 47 days, then in how many days both can finish the work together?

(8) If Mary can finish the work in 6 days and Michael can finish the same work in 11 days, then in how many days both can finish the work together?

(9) Larry can finish a work in 77 days. Scott can finish the same work in 82 days while Brandon can finish the work in 87 days. How long will it take to finish it if they work together?

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