Time and Work
MCQs Math


Question:     If Sarah can finish the work in 19 days and Joshua can finish the same work in 22 days, then in how many days both can finish the work together?


Correct Answer  10 8/41 days or 10.195 days

Solution And Explanation

Solution

Given,

The number of days to finish the work by Sarah = 19 days

And, the number of days to finish the same work by Joshua = 22 days

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

Here,

∵ In 19 days the work done by Sarah = 1

∴ In 1 day, the work done by Sarah = 1/19 part

Similarly,

∵ In 22 days the work done by Joshua = 1

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

= 1/19 + 1/22

= 22 + 19/418

= 41/418 part of work

This means in 1 day, 41/418 part of work is done by Sarah and Joshua working together.

Now, the number of days required to finish 41/418 part of work by Sarah + Joshua working together = 1

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

= 1/41/418

= 1 × 418/41 = 418/41 days

= 10 8/41 days = or 10.195 days

Thus, Sarah and Joshua working together will finish the work in 10 8/41 days = or 10.195 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 = 19 days

And the number of days required to finish the same work by Joshua = 22 days

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

Here a = 19 days

And, b = 22 days

Thus, using formula a × b/a + b days

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

= 19 × 22/19 + 22 days

= 418/41 days

= 10 8/41 days or 10.195

Thus, Sarah and Joshua together will finish the work in 10 8/41 days or 10.195 days Answer


Similar Questions

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(2) If Patricia can finish the work in 5 days and William can finish the same work in 8 days, then in how many days both can finish the work together?

(3) If Carol can finish the work in 43 days and Alexander can finish the same work in 47 days, then in how many days both can finish the work together?

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(6) If Michelle can finish the work in 44 days and Samuel can finish the same work in 49 days, then in how many days both can finish the work together?

(7) Stephanie can finish a work in 56 days. Sharon can finish the same work in 61 days while Laura can finish the work in 66 days. How long will it take to finish it if they work together?

(8) If Kimberly can finish the work in 38 days and Stephen can finish the same work in 43 days, then in how many days both can finish the work together?

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