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

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(2) Timothy can finish a work in 53 days. Edward can finish the same work in 58 days while Jason can finish the work in 63 days. How long will it take to finish it if they work together?

(3) If Christopher can finish the work in 22 days and Brian can finish the same work in 26 days, then in how many days both can finish the work together?

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(6) If Anthony can finish the work in 28 days and Jeffrey can finish the same work in 32 days, then in how many days both can finish the work together?

(7) If Robert can finish a work in 5 days and Bob can finish the same work in 6 days, then in how many days they both can finish the work working together?

(8) If Richard can finish the work in 17 days and Mark can finish the same work in 22 days, then in how many days both can finish the work together?

(9) Larry can finish a work in 77 days. Scott can finish the same work in 82 days while Brandon can finish the work in 87 days. How long will it take to finish it if they work together?

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