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

(1) 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?

(2) Gary can finish a work in 67 days. Eric can finish the same work in 72 days while Jonathan can finish the work in 77 days. How long will it take to finish it if they work together?

(3) If Christine can finish the work in 90 days and Juan can finish the same work in 95 days, then in how many days both can finish the work together?

(4) Margaret can finish a work in 32 days. Ashley can finish the same work in 37 days while Kimberly can finish the work in 42 days. How long will it take to finish it if they work together?

(5) If Christopher can finish the work in 25 days and Brian can finish the same work in 30 days, then in how many days both can finish the work together?

(6) If Linda can finish the work in 31 days and Charles can finish the same work in 47 days, then in how many days both can finish the work together?

(7) If Michael can finish the work in 30 days and Thomas can finish the same work in 46 days, then in how many days both can finish the work together?

(8) If David can finish the work in 32 days and Christopher can finish the same work in 48 days, then in how many days both can finish the work together?

(9) Sarah can finish a work in 22 days. Lisa can finish the same work in 27 days while Nancy can finish the work in 32 days. How long will it take to finish it if they work together?

(10) If George can finish the work in 48 days and Dennis can finish the same work in 52 days, then in how many days both can finish the work together?


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