Time and Work
MCQs Math


Question:     If Barbara can finish the work in 13 days and Anthony can finish the same work in 16 days, then in how many days both can finish the work together?


Correct Answer  7 5/29 days or 7.172 days

Solution And Explanation

Solution

Given,

The number of days to finish the work by Barbara = 13 days

And, the number of days to finish the same work by Anthony = 16 days

Thus, the number of days to finish the work by Barbara and Anthony together = ?

Here,

∵ In 13 days the work done by Barbara = 1

∴ In 1 day, the work done by Barbara = 1/13 part

Similarly,

∵ In 16 days the work done by Anthony = 1

∴ In 1 day, the work done by Anthony = 1/16 part

Now, in 1 day, the work done by Barbara and Anthony together

= In 1 day work done by Barbara + In 1 day the work done by Anthony

= 1/13 + 1/16

= 16 + 13/208

= 29/208 part of work

This means in 1 day, 29/208 part of work is done by Barbara and Anthony working together.

Now, the number of days required to finish 29/208 part of work by Barbara + Anthony working together = 1

∴ the number of days required to finish 1 work by Barbara + Anthony together

= 1/29/208

= 1 × 208/29 = 208/29 days

= 7 5/29 days = or 7.172 days

Thus, Barbara and Anthony working together will finish the work in 7 5/29 days = or 7.172 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 Barbara = 13 days

And the number of days required to finish the same work by Anthony = 16 days

Thus, the number of days required to finish the work Barbara and Anthony working together = ?

Here a = 13 days

And, b = 16 days

Thus, using formula a × b/a + b days

The number of days required to finish the work when Barbara and Anthony working together

= 13 × 16/13 + 16 days

= 208/29 days

= 7 5/29 days or 7.172

Thus, Barbara and Anthony together will finish the work in 7 5/29 days or 7.172 days Answer


Similar Questions

(1) If Kenneth can finish the work in 45 days and Gregory can finish the same work in 50 days, then in how many days both can finish the work together?

(2) Linda can finish a work in 8 days. Elizabeth can finish the same work in 9 days while Barbara can finish the work in 10 days. How long will it take to finish it if they work together?

(3) If Nancy can finish the work in 25 days and Ronald can finish the same work in 28 days, then in how many days both can finish the work together?

(4) If Dorothy can finish the work in 50 days and Jack can finish the same work in 55 days, then in how many days both can finish the work together?

(5) If Helen can finish the work in 84 days and Bruce can finish the same work in 89 days, then in how many days both can finish the work together?

(6) Pamela can finish a work in 78 days. Nicole can finish the same work in 83 days while Helen can finish the work in 88 days. How long will it take to finish it if they work together?

(7) 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?

(8) Jennifer can finish a work in 10 days. Elizabeth can finish the same work in 15 days while Barbara can finish the work in 20 days. How long will it take to finish it if they work together?

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