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 Brenda can finish the work in 76 days and Arthur can finish the same work in 81 days, then in how many days both can finish the work together?

(2) Andrew can finish a work in 41 days. Kenneth can finish the same work in 46 days while Kevin can finish the work in 51 days. How long will it take to finish it if they work together?

(3) If Joseph can finish the work in 19 days and Steven can finish the same work in 24 days, then in how many days both can finish the work together?

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(6) Deborah can finish a work in 50 days. Stephanie can finish the same work in 51 days while Rebecca can finish the work in 52 days. How long will it take to finish it if they work together?

(7) If Gregory can finish the work in 89 days and Alan can finish the same work in 94 days, then in how many days both can finish the work together?

(8) If Jessica can finish the work in 17 days and Paul can finish the same work in 21 days, then in how many days both can finish the work together?

(9) If Linda can finish the work in 31 days and Charles can finish the same work in 47 days, then in how many days both can finish the work together?

(10) If Joshua can finish the work in 40 days and Benjamin can finish the same work in 44 days, then in how many days both can finish the work together?


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