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

(1) If William can finish the work in 34 days and Matthew can finish the same work in 50 days, then in how many days both can finish the work together?

(2) Christopher can finish a work in 25 days. Matthew can finish the same work in 30 days while Anthony can finish the work in 35 days. How long will it take to finish it if they work together?

(3) Barbara can finish a work in 16 days. Jessica can finish the same work in 21 days while Sarah can finish the work in 26 days. How long will it take to finish it if they work together?

(4) If Lisa can finish the work in 26 days and George can finish the same work in 31 days, then in how many days both can finish the work together?

(5) Emily can finish a work in 40 days. Michelle can finish the same work in 45 days while Carol can finish the work in 50 days. How long will it take to finish it if they work together?

(6) If Patrick can finish the work in 95 days and Vincent can finish the same work in 100 days, then in how many days both can finish the work together?

(7) 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?

(8) If Deborah can finish the work in 54 days and Aaron can finish the same work in 59 days, then in how many days both can finish the work together?

(9) If Karen can finish the work in 21 days and Kevin can finish the same work in 25 days, then in how many days both can finish the work together?

(10) Larry can finish a work in 77 days. Scott can finish the same work in 82 days while Brandon can finish the work in 87 days. How long will it take to finish it if they work together?


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