Time and Work
MCQs Math


Question:     Kimberly can finish a work in 34 days. Emily can finish the same work in 35 days while Donna can finish the work in 36 days. How long will it take to finish it if they work together?


Correct Answer  11 1213/1837 days or 11.66 days

Solution And Explanation

Solution

Given,

The number of days required to finish a piece of work by Kimberly = 34 days

And, the number of days required to finish the same work by Emily = 35 days

And, the number of days required to finish the same work by Donna = 36 days

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

Here,

∵ In 34 days the work is done by Kimberly = 1

∴ The work done by Kimberly in 1 day = 1/34

Similarly,

∵ In 35 days the work is done by Emily = 1

∴ The work done by Emily in 1 day = 1/35

Similarly,

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

∴ The work done by Donna in 1 day = 1/36 part

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

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

= 1/34 + 1/35 + 1/36

= 630 + 612 + 595/21420

= 1837/21420 part of work

This means in 1 day, 1837/21420 part of work is done by Kimberly, Emily and Donna working together.

Now, the number of days required to finish 1837/21420 part of work by Kimberly, Emily, and Donna working together = 1

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

= 1/1837/21420

= 1 × 21420/1837 = 21420/1837 days

= 11 1213/1837 days = or 11.66 days

Thus, Kimberly, Emily, and Donna working together will finish the total work (1 work) in 11 1213/1837 days = or 11.66 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 Kimberly = 34 days

And the number of days required to finish the same work by Emily = 35 days

And the number of days required to finish the work by Donna = 36 days

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

Here a = 34 days

And, b = 35 days

And, c = 36 days

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

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

= 34 × 35 × 36/34 × 35 + 34 × 36 + 35 × 36 days

= 42840/1190 + 1224 + 1260 days

= 42840/3674 days

= 42840/3674 days

= 42840 ÷ 2/3674 ÷ 2 = 21420/1837 days

= 11 1213/1837 days or 11.66

Thus, Kimberly, Emily, and Donna together will finish the work in 11 1213/1837 days or 11.66 days Answer


Similar Questions

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(2) If Elizabeth can finish the work in 11 days and Daniel can finish the same work in 15 days, then in how many days both can finish the work together?

(3) Christopher can finish a work in 25 days. Matthew can finish the same work in 30 days while Anthony can finish the work in 35 days. How long will it take to finish it if they work together?

(4) If Donald can finish the work in 35 days and Nicholas can finish the same work in 40 days, then in how many days both can finish the work together?

(5) If Paul can finish the work in 36 days and Larry can finish the same work in 39 days, then in how many days both can finish the work together?

(6) If A can do a piece of work in 2 days, B can do the same piece of work in 3 days, while C alone can do the same work in 4 days. Find the number of days to finish the work when they all will work together.

(7) Kenneth can finish a work in 41 days. Kevin can finish the same work in 42 days while Brian can finish the work in 43 days. How long will it take to finish it if they work together?

(8) If Barbara can finish the work in 35 days and Anthony can finish the same work in 51 days, then in how many days both can finish the work together?

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(10) If Anthony can finish the work in 28 days and Jeffrey can finish the same work in 31 days, then in how many days both can finish the work together?


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