Time and Work
MCQs Math


Question:     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?


Correct Answer  3 1/13 days or 3.077 days

Solution And Explanation

Solution

Given,

The number of days to finish the work by Patricia = 5 days

And, the number of days to finish the same work by William = 8 days

Thus, the number of days to finish the work by Patricia and William together = ?

Here,

∵ In 5 days the work done by Patricia = 1

∴ In 1 day, the work done by Patricia = 1/5 part

Similarly,

∵ In 8 days the work done by William = 1

∴ In 1 day, the work done by William = 1/8 part

Now, in 1 day, the work done by Patricia and William together

= In 1 day work done by Patricia + In 1 day the work done by William

= 1/5 + 1/8

= 8 + 5/40

= 13/40 part of work

This means in 1 day, 13/40 part of work is done by Patricia and William working together.

Now, the number of days required to finish 13/40 part of work by Patricia + William working together = 1

∴ the number of days required to finish 1 work by Patricia + William together

= 1/13/40

= 1 × 40/13 = 40/13 days

= 3 1/13 days = or 3.077 days

Thus, Patricia and William working together will finish the work in 3 1/13 days = or 3.077 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 Patricia = 5 days

And the number of days required to finish the same work by William = 8 days

Thus, the number of days required to finish the work Patricia and William working together = ?

Here a = 5 days

And, b = 8 days

Thus, using formula a × b/a + b days

The number of days required to finish the work when Patricia and William working together

= 5 × 8/5 + 8 days

= 40/13 days

= 3 1/13 days or 3.077

Thus, Patricia and William together will finish the work in 3 1/13 days or 3.077 days Answer


Similar Questions

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(2) If Donna can finish the work in 39 days and Brandon can finish the same work in 42 days, then in how many days both can finish the work together?

(3) Steven can finish a work in 37 days. Andrew can finish the same work in 42 days while Joshua can finish the work in 47 days. How long will it take to finish it if they work together?

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(7) 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?

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(9) Samantha can finish a work in 86 days. Christine can finish the same work in 91 days while Debra can finish the work in 96 days. How long will it take to finish it if they work together?

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