Time and Work
MCQs Math


Question:     If Sarah can finish the work in 22 days and Joshua can finish the same work in 27 days, then in how many days both can finish the work together?


Correct Answer  12 6/49 days or 12.122 days

Solution And Explanation

Solution

Given,

The number of days to finish the work by Sarah = 22 days

And, the number of days to finish the same work by Joshua = 27 days

Thus, the number of days to finish the work by Sarah and Joshua together = ?

Here,

∵ In 22 days the work done by Sarah = 1

∴ In 1 day, the work done by Sarah = 1/22 part

Similarly,

∵ In 27 days the work done by Joshua = 1

∴ In 1 day, the work done by Joshua = 1/27 part

Now, in 1 day, the work done by Sarah and Joshua together

= In 1 day work done by Sarah + In 1 day the work done by Joshua

= 1/22 + 1/27

= 27 + 22/594

= 49/594 part of work

This means in 1 day, 49/594 part of work is done by Sarah and Joshua working together.

Now, the number of days required to finish 49/594 part of work by Sarah + Joshua working together = 1

∴ the number of days required to finish 1 work by Sarah + Joshua together

= 1/49/594

= 1 × 594/49 = 594/49 days

= 12 6/49 days = or 12.122 days

Thus, Sarah and Joshua working together will finish the work in 12 6/49 days = or 12.122 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 Sarah = 22 days

And the number of days required to finish the same work by Joshua = 27 days

Thus, the number of days required to finish the work Sarah and Joshua working together = ?

Here a = 22 days

And, b = 27 days

Thus, using formula a × b/a + b days

The number of days required to finish the work when Sarah and Joshua working together

= 22 × 27/22 + 27 days

= 594/49 days

= 12 6/49 days or 12.122

Thus, Sarah and Joshua together will finish the work in 12 6/49 days or 12.122 days Answer


Similar Questions

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(6) If Robert can finish the work in 26 days and David can finish the same work in 42 days, then in how many days both can finish the work together?

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(8) Jessica can finish a work in 20 days. Karen can finish the same work in 25 days while Lisa can finish the work in 30 days. How long will it take to finish it if they work together?

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