Time and Work
MCQs Math


Question:     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?


Correct Answer  14 42/59 days or 14.712 days

Solution And Explanation

Solution

Given,

The number of days to finish the work by Anthony = 28 days

And, the number of days to finish the same work by Jeffrey = 31 days

Thus, the number of days to finish the work by Anthony and Jeffrey together = ?

Here,

∵ In 28 days the work done by Anthony = 1

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

Similarly,

∵ In 31 days the work done by Jeffrey = 1

∴ In 1 day, the work done by Jeffrey = 1/31 part

Now, in 1 day, the work done by Anthony and Jeffrey together

= In 1 day work done by Anthony + In 1 day the work done by Jeffrey

= 1/28 + 1/31

= 31 + 28/868

= 59/868 part of work

This means in 1 day, 59/868 part of work is done by Anthony and Jeffrey working together.

Now, the number of days required to finish 59/868 part of work by Anthony + Jeffrey working together = 1

∴ the number of days required to finish 1 work by Anthony + Jeffrey together

= 1/59/868

= 1 × 868/59 = 868/59 days

= 14 42/59 days = or 14.712 days

Thus, Anthony and Jeffrey working together will finish the work in 14 42/59 days = or 14.712 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 Anthony = 28 days

And the number of days required to finish the same work by Jeffrey = 31 days

Thus, the number of days required to finish the work Anthony and Jeffrey working together = ?

Here a = 28 days

And, b = 31 days

Thus, using formula a × b/a + b days

The number of days required to finish the work when Anthony and Jeffrey working together

= 28 × 31/28 + 31 days

= 868/59 days

= 14 42/59 days or 14.712

Thus, Anthony and Jeffrey together will finish the work in 14 42/59 days or 14.712 days Answer


Similar Questions

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(2) 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?

(3) 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?

(4) If Charles can finish the work in 23 days and Kenneth can finish the same work in 28 days, then in how many days both can finish the work together?

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(6) If William can finish the work in 34 days and Matthew can finish the same work in 50 days, then in how many days both can finish the work together?

(7) 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?

(8) 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?

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