Time and Work
MCQs Math


Question:     If Jonathan can finish the work in 73 days and Sean can finish the same work in 78 days, then in how many days both can finish the work together?


Correct Answer  37 107/151 days or 37.709 days

Solution And Explanation

Solution

Given,

The number of days to finish the work by Jonathan = 73 days

And, the number of days to finish the same work by Sean = 78 days

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

Here,

∵ In 73 days the work done by Jonathan = 1

∴ In 1 day, the work done by Jonathan = 1/73 part

Similarly,

∵ In 78 days the work done by Sean = 1

∴ In 1 day, the work done by Sean = 1/78 part

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

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

= 1/73 + 1/78

= 78 + 73/5694

= 151/5694 part of work

This means in 1 day, 151/5694 part of work is done by Jonathan and Sean working together.

Now, the number of days required to finish 151/5694 part of work by Jonathan + Sean working together = 1

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

= 1/151/5694

= 1 × 5694/151 = 5694/151 days

= 37 107/151 days = or 37.709 days

Thus, Jonathan and Sean working together will finish the work in 37 107/151 days = or 37.709 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 Jonathan = 73 days

And the number of days required to finish the same work by Sean = 78 days

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

Here a = 73 days

And, b = 78 days

Thus, using formula a × b/a + b days

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

= 73 × 78/73 + 78 days

= 5694/151 days

= 37 107/151 days or 37.709

Thus, Jonathan and Sean together will finish the work in 37 107/151 days or 37.709 days Answer


Similar Questions

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(2) Jack can finish a work in 99 days. Jerry can finish the same work in 104 days while Tyler can finish the work in 109 days. How long will it take to finish it if they work together?

(3) Michelle can finish a work in 40 days. Carol can finish the same work in 41 days while Amanda can finish the work in 42 days. How long will it take to finish it if they work together?

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(6) If Nicholas can finish the work in 69 days and Roger can finish the same work in 74 days, then in how many days both can finish the work together?

(7) If Sharon can finish the work in 60 days and Zachary can finish the same work in 65 days, then in how many days both can finish the work together?

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(9) If John can finish the work in 6 days and Richard can finish the same work in 9 days, then in how many days both can finish the work together?

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