Time and Work
MCQs Math


Question:     If Steven can finish the work in 37 days and Jonathan can finish the same work in 42 days, then in how many days both can finish the work together?


Correct Answer  19 53/79 days or 19.671 days

Solution And Explanation

Solution

Given,

The number of days to finish the work by Steven = 37 days

And, the number of days to finish the same work by Jonathan = 42 days

Thus, the number of days to finish the work by Steven and Jonathan together = ?

Here,

∵ In 37 days the work done by Steven = 1

∴ In 1 day, the work done by Steven = 1/37 part

Similarly,

∵ In 42 days the work done by Jonathan = 1

∴ In 1 day, the work done by Jonathan = 1/42 part

Now, in 1 day, the work done by Steven and Jonathan together

= In 1 day work done by Steven + In 1 day the work done by Jonathan

= 1/37 + 1/42

= 42 + 37/1554

= 79/1554 part of work

This means in 1 day, 79/1554 part of work is done by Steven and Jonathan working together.

Now, the number of days required to finish 79/1554 part of work by Steven + Jonathan working together = 1

∴ the number of days required to finish 1 work by Steven + Jonathan together

= 1/79/1554

= 1 × 1554/79 = 1554/79 days

= 19 53/79 days = or 19.671 days

Thus, Steven and Jonathan working together will finish the work in 19 53/79 days = or 19.671 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 Steven = 37 days

And the number of days required to finish the same work by Jonathan = 42 days

Thus, the number of days required to finish the work Steven and Jonathan working together = ?

Here a = 37 days

And, b = 42 days

Thus, using formula a × b/a + b days

The number of days required to finish the work when Steven and Jonathan working together

= 37 × 42/37 + 42 days

= 1554/79 days

= 19 53/79 days or 19.671

Thus, Steven and Jonathan together will finish the work in 19 53/79 days or 19.671 days Answer


Similar Questions

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(2) If Rachel can finish the work in 94 days and Roy can finish the same work in 99 days, then in how many days both can finish the work together?

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(6) 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?

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