Time and Work
MCQs Math


Question:     If Lisa can finish the work in 23 days and George can finish the same work in 26 days, then in how many days both can finish the work together?


Correct Answer  12 10/49 days or 12.204 days

Solution And Explanation

Solution

Given,

The number of days to finish the work by Lisa = 23 days

And, the number of days to finish the same work by George = 26 days

Thus, the number of days to finish the work by Lisa and George together = ?

Here,

∵ In 23 days the work done by Lisa = 1

∴ In 1 day, the work done by Lisa = 1/23 part

Similarly,

∵ In 26 days the work done by George = 1

∴ In 1 day, the work done by George = 1/26 part

Now, in 1 day, the work done by Lisa and George together

= In 1 day work done by Lisa + In 1 day the work done by George

= 1/23 + 1/26

= 26 + 23/598

= 49/598 part of work

This means in 1 day, 49/598 part of work is done by Lisa and George working together.

Now, the number of days required to finish 49/598 part of work by Lisa + George working together = 1

∴ the number of days required to finish 1 work by Lisa + George together

= 1/49/598

= 1 × 598/49 = 598/49 days

= 12 10/49 days = or 12.204 days

Thus, Lisa and George working together will finish the work in 12 10/49 days = or 12.204 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 Lisa = 23 days

And the number of days required to finish the same work by George = 26 days

Thus, the number of days required to finish the work Lisa and George working together = ?

Here a = 23 days

And, b = 26 days

Thus, using formula a × b/a + b days

The number of days required to finish the work when Lisa and George working together

= 23 × 26/23 + 26 days

= 598/49 days

= 12 10/49 days or 12.204

Thus, Lisa and George together will finish the work in 12 10/49 days or 12.204 days Answer


Similar Questions

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(2) Jennifer can finish a work in 6 days. Linda can finish the same work in 7 days while Elizabeth can finish the work in 8 days. How long will it take to finish it if they work together?

(3) If Gregory can finish the work in 89 days and Alan can finish the same work in 94 days, then in how many days both can finish the work together?

(4) If Lisa can finish the work in 23 days and George can finish the same work in 27 days, then in how many days both can finish the work together?

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(6) If Ashley can finish the work in 33 days and Eric can finish the same work in 37 days, then in how many days both can finish the work together?

(7) Edward can finish a work in 57 days. Jeffrey can finish the same work in 62 days while Ryan can finish the work in 67 days. How long will it take to finish it if they work together?

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