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

(1) If Jennifer can finish the work in 7 days and Joseph can finish the same work in 11 days, then in how many days both can finish the work together?

(2) If Edward can finish the work in 57 days and Nathan can finish the same work in 62 days, then in how many days both can finish the work together?

(3) Nancy can finish a work in 28 days. Margaret can finish the same work in 33 days while Sandra can finish the work in 38 days. How long will it take to finish it if they work together?

(4) Nancy can finish a work in 24 days. Betty can finish the same work in 25 days while Margaret can finish the work in 26 days. How long will it take to finish it if they work together?

(5) If James can finish the work in 2 days and John can finish the same work in 5 days, then in how many days both can finish the work together?

(6) If Betty can finish the work in 30 days and Jason can finish the same work in 35 days, then in how many days both can finish the work together?

(7) If Myra can finish the work in 15 days and Sophia can finish the same work in 20 days, then in how many days they both can finish the work working together?

(8) If Barbara can finish the work in 13 days and Anthony can finish the same work in 16 days, then in how many days both can finish the work together?

(9) Christopher can finish a work in 21 days. Daniel can finish the same work in 22 days while Matthew can finish the work in 23 days. How long will it take to finish it if they work together?

(10) If Joseph can finish the work in 16 days and Steven can finish the same work in 20 days, then in how many days both can finish the work together?


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