Time and Work
MCQs Math


Question:     Betty can finish a work in 26 days. Margaret can finish the same work in 27 days while Sandra can finish the work in 28 days. How long will it take to finish it if they work together?


Correct Answer  8 1084/1093 days or 8.992 days

Solution And Explanation

Solution

Given,

The number of days required to finish a piece of work by Betty = 26 days

And, the number of days required to finish the same work by Margaret = 27 days

And, the number of days required to finish the same work by Sandra = 28 days

Thus, the number of days required to finish the work by all of them if they work together = ?

Here,

∵ In 26 days the work is done by Betty = 1

∴ The work done by Betty in 1 day = 1/26

Similarly,

∵ In 27 days the work is done by Margaret = 1

∴ The work done by Margaret in 1 day = 1/27

Similarly,

∵ In 28 days the work is done by Sandra = 1

∴ The work done by Sandra in 1 day = 1/28 part

Now, the work done by Betty, Margaret, and Sandra together in 1 day

= Betty's 1 day work + Margaret's 1 day work + Sandra's 1 day work

= 1/26 + 1/27 + 1/28

= 378 + 364 + 351/9828

= 1093/9828 part of work

This means in 1 day, 1093/9828 part of work is done by Betty, Margaret and Sandra working together.

Now, the number of days required to finish 1093/9828 part of work by Betty, Margaret, and Sandra working together = 1

∴ the number of days required to finish the whole work (1 work) by Betty + Margaret + Sandra together

= 1/1093/9828

= 1 × 9828/1093 = 9828/1093 days

= 8 1084/1093 days = or 8.992 days

Thus, Betty, Margaret, and Sandra working together will finish the total work (1 work) in 8 1084/1093 days = or 8.992 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, B can finish the same work in b days, and C can finish the work in c days
then working together the number of days required to finish the work
= a × b × c/ab + ac + bc days.

Here given,

The number of days required to finish the work by Betty = 26 days

And the number of days required to finish the same work by Margaret = 27 days

And the number of days required to finish the work by Sandra = 28 days

Thus, the number of days required to finish the work by Betty, Margaret, and Sandra together = ?

Here a = 26 days

And, b = 27 days

And, c = 28 days

Thus, using formula a × b × c/ab + ac + bc days

The number of days required to finish the work when Betty, Margaret, and Sandra working together

= 26 × 27 × 28/26 × 27 + 26 × 28 + 27 × 28 days

= 19656/702 + 728 + 756 days

= 19656/2186 days

= 19656/2186 days

= 19656 ÷ 2/2186 ÷ 2 = 9828/1093 days

= 8 1084/1093 days or 8.992

Thus, Betty, Margaret, and Sandra together will finish the work in 8 1084/1093 days or 8.992 days Answer


Similar Questions

(1) If Amanda can finish the work in 45 days and Patrick can finish the same work in 48 days, then in how many days both can finish the work together?

(2) Daniel can finish a work in 27 days. Anthony can finish the same work in 32 days while Mark can finish the work in 37 days. How long will it take to finish it if they work together?

(3) If Timothy can finish the work in 53 days and Tyler can finish the same work in 58 days, then in how many days both can finish the work together?

(4) 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?

(5) If Myra can finish the work in 25 days and Sophia can finish the same work in 15 days, then in how many days they both can finish the work working together?

(6) If Barbara can finish the work in 13 days and Anthony can finish the same work in 17 days, then in how many days both can finish the work together?

(7) If Patricia can finish the work in 27 days and William can finish the same work in 43 days, then in how many days both can finish the work together?

(8) If Emily can finish the work in 37 days and Justin can finish the same work in 40 days, then in how many days both can finish the work together?

(9) Nicole can finish a work in 82 days. Samantha can finish the same work in 87 days while Katherine can finish the work in 92 days. How long will it take to finish it if they work together?

(10) If Anthony can finish the work in 31 days and Jeffrey can finish the same work in 36 days, then in how many days both can finish the work together?


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