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

(1) If Lisa can finish the work in 26 days and George can finish the same work in 31 days, then in how many days both can finish the work together?

(2) If Stephanie can finish the work in 56 days and Adam can finish the same work in 61 days, then in how many days both can finish the work together?

(3) If Emma can finish the work in 80 days and Jordan can finish the same work in 85 days, then in how many days both can finish the work together?

(4) Michelle can finish a work in 44 days. Amanda can finish the same work in 49 days while Dorothy can finish the work in 54 days. How long will it take to finish it if they work together?

(5) Thomas can finish a work in 17 days. Charles can finish the same work in 18 days while Christopher can finish the work in 19 days. How long will it take to finish it if they work together?

(6) If Amanda can finish the work in 48 days and Patrick can finish the same work in 53 days, then in how many days both can finish the work together?

(7) Amy can finish a work in 68 days. Shirley can finish the same work in 73 days while Anna can finish the work in 78 days. How long will it take to finish it if they work together?

(8) If Dorothy can finish the work in 47 days and Jack can finish the same work in 50 days, then in how many days both can finish the work together?

(9) If Amy can finish the work in 68 days and Keith can finish the same work in 73 days, then in how many days both can finish the work together?

(10) If Michelle can finish the work in 41 days and Samuel can finish the same work in 45 days, then in how many days both can finish the work together?


NCERT Solution and CBSE Notes for class twelve, eleventh, tenth, ninth, seventh, sixth, fifth, fourth and General Math for competitive Exams. ©