Time and Work
MCQs Math


Question:     If Nicole can finish the work in 82 days and Billy can finish the same work in 87 days, then in how many days both can finish the work together?


Correct Answer  42 36/169 days or 42.213 days

Solution And Explanation

Solution

Given,

The number of days to finish the work by Nicole = 82 days

And, the number of days to finish the same work by Billy = 87 days

Thus, the number of days to finish the work by Nicole and Billy together = ?

Here,

∵ In 82 days the work done by Nicole = 1

∴ In 1 day, the work done by Nicole = 1/82 part

Similarly,

∵ In 87 days the work done by Billy = 1

∴ In 1 day, the work done by Billy = 1/87 part

Now, in 1 day, the work done by Nicole and Billy together

= In 1 day work done by Nicole + In 1 day the work done by Billy

= 1/82 + 1/87

= 87 + 82/7134

= 169/7134 part of work

This means in 1 day, 169/7134 part of work is done by Nicole and Billy working together.

Now, the number of days required to finish 169/7134 part of work by Nicole + Billy working together = 1

∴ the number of days required to finish 1 work by Nicole + Billy together

= 1/169/7134

= 1 × 7134/169 = 7134/169 days

= 42 36/169 days = or 42.213 days

Thus, Nicole and Billy working together will finish the work in 42 36/169 days = or 42.213 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 Nicole = 82 days

And the number of days required to finish the same work by Billy = 87 days

Thus, the number of days required to finish the work Nicole and Billy working together = ?

Here a = 82 days

And, b = 87 days

Thus, using formula a × b/a + b days

The number of days required to finish the work when Nicole and Billy working together

= 82 × 87/82 + 87 days

= 7134/169 days

= 42 36/169 days or 42.213

Thus, Nicole and Billy together will finish the work in 42 36/169 days or 42.213 days Answer


Similar Questions

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(2) If Edward can finish the work in 57 days and Nathan can finish the same work in 62 days, then in how many days both can finish the work together?

(3) William can finish a work in 11 days. Richard can finish the same work in 12 days while Joseph can finish the work in 13 days. How long will it take to finish it if they work together?

(4) William can finish a work in 15 days. Joseph can finish the same work in 20 days while Thomas can finish the work in 25 days. How long will it take to finish it if they work together?

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(6) Karen can finish a work in 24 days. Nancy can finish the same work in 29 days while Betty can finish the work in 34 days. How long will it take to finish it if they work together?

(7) If Kimberly can finish the work in 35 days and Stephen can finish the same work in 39 days, then in how many days both can finish the work together?

(8) Susan can finish a work in 14 days. Jessica can finish the same work in 15 days while Sarah can finish the work in 16 days. How long will it take to finish it if they work together?

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(10) If Daniel can finish the work in 27 days and Timothy can finish the same work in 32 days, then in how many days both can finish the work together?


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