Time and Work
MCQs Math


Question:     If Andrew can finish the work in 38 days and Scott can finish the same work in 41 days, then in how many days both can finish the work together?


Correct Answer  19 57/79 days or 19.722 days

Solution And Explanation

Solution

Given,

The number of days to finish the work by Andrew = 38 days

And, the number of days to finish the same work by Scott = 41 days

Thus, the number of days to finish the work by Andrew and Scott together = ?

Here,

∵ In 38 days the work done by Andrew = 1

∴ In 1 day, the work done by Andrew = 1/38 part

Similarly,

∵ In 41 days the work done by Scott = 1

∴ In 1 day, the work done by Scott = 1/41 part

Now, in 1 day, the work done by Andrew and Scott together

= In 1 day work done by Andrew + In 1 day the work done by Scott

= 1/38 + 1/41

= 41 + 38/1558

= 79/1558 part of work

This means in 1 day, 79/1558 part of work is done by Andrew and Scott working together.

Now, the number of days required to finish 79/1558 part of work by Andrew + Scott working together = 1

∴ the number of days required to finish 1 work by Andrew + Scott together

= 1/79/1558

= 1 × 1558/79 = 1558/79 days

= 19 57/79 days = or 19.722 days

Thus, Andrew and Scott working together will finish the work in 19 57/79 days = or 19.722 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 Andrew = 38 days

And the number of days required to finish the same work by Scott = 41 days

Thus, the number of days required to finish the work Andrew and Scott working together = ?

Here a = 38 days

And, b = 41 days

Thus, using formula a × b/a + b days

The number of days required to finish the work when Andrew and Scott working together

= 38 × 41/38 + 41 days

= 1558/79 days

= 19 57/79 days or 19.722

Thus, Andrew and Scott together will finish the work in 19 57/79 days or 19.722 days Answer


Similar Questions

(1) 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?

(2) 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?

(3) If Pamela can finish the work in 78 days and Dylan can finish the same work in 83 days, then in how many days both can finish the work together?

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(6) Jonathan can finish a work in 73 days. Larry can finish the same work in 78 days while Justin can finish the work in 83 days. How long will it take to finish it if they work together?

(7) If Charles can finish the work in 20 days and Kenneth can finish the same work in 24 days, then in how many days both can finish the work together?

(8) Lisa can finish a work in 26 days. Betty can finish the same work in 31 days while Margaret can finish the work in 36 days. How long will it take to finish it if they work together?

(9) Nicole can finish a work in 82 days. Samantha can finish the same work in 87 days while Katherine can finish the work in 92 days. How long will it take to finish it if they work together?

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