Time and Work
MCQs Math


Question:     If Shirley can finish the work in 72 days and Harold can finish the same work in 77 days, then in how many days both can finish the work together?


Correct Answer  37 31/149 days or 37.208 days

Solution And Explanation

Solution

Given,

The number of days to finish the work by Shirley = 72 days

And, the number of days to finish the same work by Harold = 77 days

Thus, the number of days to finish the work by Shirley and Harold together = ?

Here,

∵ In 72 days the work done by Shirley = 1

∴ In 1 day, the work done by Shirley = 1/72 part

Similarly,

∵ In 77 days the work done by Harold = 1

∴ In 1 day, the work done by Harold = 1/77 part

Now, in 1 day, the work done by Shirley and Harold together

= In 1 day work done by Shirley + In 1 day the work done by Harold

= 1/72 + 1/77

= 77 + 72/5544

= 149/5544 part of work

This means in 1 day, 149/5544 part of work is done by Shirley and Harold working together.

Now, the number of days required to finish 149/5544 part of work by Shirley + Harold working together = 1

∴ the number of days required to finish 1 work by Shirley + Harold together

= 1/149/5544

= 1 × 5544/149 = 5544/149 days

= 37 31/149 days = or 37.208 days

Thus, Shirley and Harold working together will finish the work in 37 31/149 days = or 37.208 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 Shirley = 72 days

And the number of days required to finish the same work by Harold = 77 days

Thus, the number of days required to finish the work Shirley and Harold working together = ?

Here a = 72 days

And, b = 77 days

Thus, using formula a × b/a + b days

The number of days required to finish the work when Shirley and Harold working together

= 72 × 77/72 + 77 days

= 5544/149 days

= 37 31/149 days or 37.208

Thus, Shirley and Harold together will finish the work in 37 31/149 days or 37.208 days Answer


Similar Questions

(1) Ashley can finish a work in 32 days. Kimberly can finish the same work in 33 days while Emily can finish the work in 34 days. How long will it take to finish it if they work together?

(2) If Jacob can finish the work in 65 days and Noah can finish the same work in 70 days, then in how many days both can finish the work together?

(3) If Shirley can finish the work in 72 days and Harold can finish the same work in 77 days, then in how many days both can finish the work together?

(4) 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?

(5) Betty can finish a work in 30 days. Sandra can finish the same work in 35 days while Ashley can finish the work in 40 days. How long will it take to finish it if they work together?

(6) Joshua can finish a work in 43 days. Kevin can finish the same work in 48 days while Brian can finish the work in 53 days. How long will it take to finish it if they work together?

(7) If Robert can finish the work in 26 days and David can finish the same work in 42 days, then in how many days both can finish the work together?

(8) If Nicholas can finish the work in 69 days and Roger can finish the same work in 74 days, then in how many days both can finish the work together?

(9) Patricia can finish a work in 4 days. Jennifer can finish the same work in 5 days while Linda can finish the work in 6 days. How long will it take to finish it if they work together?

(10) Laura can finish a work in 62 days. Kathleen can finish the same work in 67 days while Amy can finish the work in 72 days. How long will it take to finish it if they work together?


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