Time and Work
MCQs Math


Question:     If Nancy can finish the work in 25 days and Ronald can finish the same work in 28 days, then in how many days both can finish the work together?


Correct Answer  13 11/53 days or 13.208 days

Solution And Explanation

Solution

Given,

The number of days to finish the work by Nancy = 25 days

And, the number of days to finish the same work by Ronald = 28 days

Thus, the number of days to finish the work by Nancy and Ronald together = ?

Here,

∵ In 25 days the work done by Nancy = 1

∴ In 1 day, the work done by Nancy = 1/25 part

Similarly,

∵ In 28 days the work done by Ronald = 1

∴ In 1 day, the work done by Ronald = 1/28 part

Now, in 1 day, the work done by Nancy and Ronald together

= In 1 day work done by Nancy + In 1 day the work done by Ronald

= 1/25 + 1/28

= 28 + 25/700

= 53/700 part of work

This means in 1 day, 53/700 part of work is done by Nancy and Ronald working together.

Now, the number of days required to finish 53/700 part of work by Nancy + Ronald working together = 1

∴ the number of days required to finish 1 work by Nancy + Ronald together

= 1/53/700

= 1 × 700/53 = 700/53 days

= 13 11/53 days = or 13.208 days

Thus, Nancy and Ronald working together will finish the work in 13 11/53 days = or 13.208 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, and B can finish the same work in b days,
then working together the number of days require to finish the work
= a × b/a + b days.

Here given,

The number of days required to finish the work by Nancy = 25 days

And the number of days required to finish the same work by Ronald = 28 days

Thus, the number of days required to finish the work Nancy and Ronald working together = ?

Here a = 25 days

And, b = 28 days

Thus, using formula a × b/a + b days

The number of days required to finish the work when Nancy and Ronald working together

= 25 × 28/25 + 28 days

= 700/53 days

= 13 11/53 days or 13.208

Thus, Nancy and Ronald together will finish the work in 13 11/53 days or 13.208 days Answer


Similar Questions

(1) Carol can finish a work in 42 days. Amanda can finish the same work in 43 days while Dorothy can finish the work in 44 days. How long will it take to finish it if they work together?

(2) If Steven can finish the work in 34 days and Jonathan can finish the same work in 38 days, then in how many days both can finish the work together?

(3) Katherine can finish a work in 88 days. Debra can finish the same work in 93 days while Rachel can finish the work in 98 days. How long will it take to finish it if they work together?

(4) Raymond can finish a work in 97 days. Dennis can finish the same work in 102 days while Jerry can finish the work in 107 days. How long will it take to finish it if they 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 Jack can finish the work in 20 days and Bill can finish the same work in 30 days, then in how many days they both can finish the work working together?

(8) Timothy can finish a work in 49 days. Ronald can finish the same work in 50 days while Edward can finish the work in 51 days. How long will it take to finish it if they work together?

(9) 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?

(10) If John can finish the work in 6 days and Richard can finish the same work in 9 days, then in how many days both can finish the work together?


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