Time and Work
MCQs Math


Question:     If Daniel can finish the work in 24 days and Timothy can finish the same work in 28 days, then in how many days both can finish the work together?


Correct Answer  12 12/13 days or 12.923 days

Solution And Explanation

Solution

Given,

The number of days to finish the work by Daniel = 24 days

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

Thus, the number of days to finish the work by Daniel and Timothy together = ?

Here,

∵ In 24 days the work done by Daniel = 1

∴ In 1 day, the work done by Daniel = 1/24 part

Similarly,

∵ In 28 days the work done by Timothy = 1

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

Now, in 1 day, the work done by Daniel and Timothy together

= In 1 day work done by Daniel + In 1 day the work done by Timothy

= 1/24 + 1/28

= 7 + 6/168

= 13/168 part of work

This means in 1 day, 13/168 part of work is done by Daniel and Timothy working together.

Now, the number of days required to finish 13/168 part of work by Daniel + Timothy working together = 1

∴ the number of days required to finish 1 work by Daniel + Timothy together

= 1/13/168

= 1 × 168/13 = 168/13 days

= 12 12/13 days = or 12.923 days

Thus, Daniel and Timothy working together will finish the work in 12 12/13 days = or 12.923 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 Daniel = 24 days

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

Thus, the number of days required to finish the work Daniel and Timothy working together = ?

Here a = 24 days

And, b = 28 days

Thus, using formula a × b/a + b days

The number of days required to finish the work when Daniel and Timothy working together

= 24 × 28/24 + 28 days

= 672/52 days

= 672 ÷ 4/52 ÷ 4 = 168/13 days

= 12 12/13 days or 12.923

Thus, Daniel and Timothy together will finish the work in 12 12/13 days or 12.923 days Answer


Similar Questions

(1) If John can finish the work in 9 days and Richard can finish the same work in 14 days, then in how many days both can finish the work together?

(2) Michael can finish a work in 11 days. William can finish the same work in 16 days while Richard can finish the work in 21 days. How long will it take to finish it if they work together?

(3) If Mark can finish the work in 33 days and Jacob can finish the same work in 38 days, then in how many days both can finish the work together?

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(6) Margaret can finish a work in 32 days. Ashley can finish the same work in 37 days while Kimberly can finish the work in 42 days. How long will it take to finish it if they work together?

(7) Patricia can finish a work in 4 days. Jennifer can finish the same work in 5 days while Linda can finish the work in 6 days. How long will it take to finish it if they work together?

(8) If Ashley can finish the work in 33 days and Eric can finish the same work in 36 days, then in how many days both can finish the work together?

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