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 Annie can finish a work in 2 days and Bobby can finish the same work in 3 days, then in how many days they both can finish the work working together?

(2) Richard can finish a work in 13 days. Joseph can finish the same work in 14 days while Thomas can finish the work in 15 days. How long will it take to finish it if they work together?

(3) If Karen can finish the work in 21 days and Kevin can finish the same work in 24 days, then in how many days both can finish the work together?

(4) If Donald can finish the work in 35 days and Nicholas can finish the same work in 40 days, then in how many days both can finish the work together?

(5) If Rebecca can finish the work in 58 days and Henry can finish the same work in 63 days, then in how many days both can finish the work together?

(6) If Brandon can finish the work in 83 days and Joe can finish the same work in 88 days, then in how many days both can finish the work together?

(7) Samuel can finish a work in 87 days. Alexander can finish the same work in 92 days while Frank can finish the work in 97 days. How long will it take to finish it if they work together?

(8) If Linda can finish the work in 9 days and Charles can finish the same work in 13 days, then in how many days both can finish the work together?

(9) If Elizabeth can finish the work in 33 days and Daniel can finish the same work in 49 days, then in how many days both can finish the work together?

(10) Brenda can finish a work in 76 days. Emma can finish the same work in 81 days while Nicole can finish the work in 86 days. How long will it take to finish it if they work together?


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