Time and Work
MCQs Math


Question:     Nancy can finish a work in 28 days. Margaret can finish the same work in 33 days while Sandra can finish the work in 38 days. How long will it take to finish it if they work together?


Correct Answer  10 1346/1621 days or 10.83 days

Solution And Explanation

Solution

Given,

The number of days required to finish a piece of work by Nancy = 28 days

And, the number of days required to finish the same work by Margaret = 33 days

And, the number of days required to finish the same work by Sandra = 38 days

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

Here,

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

∴ The work done by Nancy in 1 day = 1/28

Similarly,

∵ In 33 days the work is done by Margaret = 1

∴ The work done by Margaret in 1 day = 1/33

Similarly,

∵ In 38 days the work is done by Sandra = 1

∴ The work done by Sandra in 1 day = 1/38 part

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

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

= 1/28 + 1/33 + 1/38

= 627 + 532 + 462/17556

= 1621/17556 part of work

This means in 1 day, 1621/17556 part of work is done by Nancy, Margaret and Sandra working together.

Now, the number of days required to finish 1621/17556 part of work by Nancy, Margaret, and Sandra working together = 1

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

= 1/1621/17556

= 1 × 17556/1621 = 17556/1621 days

= 10 1346/1621 days = or 10.83 days

Thus, Nancy, Margaret, and Sandra working together will finish the total work (1 work) in 10 1346/1621 days = or 10.83 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 Nancy = 28 days

And the number of days required to finish the same work by Margaret = 33 days

And the number of days required to finish the work by Sandra = 38 days

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

Here a = 28 days

And, b = 33 days

And, c = 38 days

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

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

= 28 × 33 × 38/28 × 33 + 28 × 38 + 33 × 38 days

= 35112/924 + 1064 + 1254 days

= 35112/3242 days

= 35112/3242 days

= 35112 ÷ 2/3242 ÷ 2 = 17556/1621 days

= 10 1346/1621 days or 10.83

Thus, Nancy, Margaret, and Sandra together will finish the work in 10 1346/1621 days or 10.83 days Answer


Similar Questions

(1) If Jason can finish the work in 59 days and Douglas can finish the same work in 64 days, then in how many days both can finish the work together?

(2) If Carol can finish the work in 43 days and Alexander can finish the same work in 46 days, then in how many days both can finish the work together?

(3) 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?

(4) If Sharon can finish the work in 60 days and Zachary can finish the same work in 65 days, then in how many days both can finish the work together?

(5) Karen can finish a work in 20 days. Lisa can finish the same work in 21 days while Nancy can finish the work in 22 days. How long will it take to finish it if they work together?

(6) 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?

(7) If Anthony can finish the work in 28 days and Jeffrey can finish the same work in 32 days, then in how many days both can finish the work together?

(8) Mary can finish a work in 6 days. Jennifer can finish the same work in 11 days while Linda can finish the work in 16 days. How long will it take to finish it if they work together?

(9) If Steven can finish the work in 37 days and Jonathan can finish the same work in 42 days, then in how many days both can finish the work together?

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