Time and Work
MCQs Math


Question:     Donald can finish a work in 31 days. Steven can finish the same work in 32 days while Paul can finish the work in 33 days. How long will it take to finish it if they work together?


Correct Answer  10 2026/3071 days or 10.66 days

Solution And Explanation

Solution

Given,

The number of days required to finish a piece of work by Donald = 31 days

And, the number of days required to finish the same work by Steven = 32 days

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

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

Here,

∵ In 31 days the work is done by Donald = 1

∴ The work done by Donald in 1 day = 1/31

Similarly,

∵ In 32 days the work is done by Steven = 1

∴ The work done by Steven in 1 day = 1/32

Similarly,

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

∴ The work done by Paul in 1 day = 1/33 part

Now, the work done by Donald, Steven, and Paul together in 1 day

= Donald's 1 day work + Steven's 1 day work + Paul's 1 day work

= 1/31 + 1/32 + 1/33

= 1056 + 1023 + 992/32736

= 3071/32736 part of work

This means in 1 day, 3071/32736 part of work is done by Donald, Steven and Paul working together.

Now, the number of days required to finish 3071/32736 part of work by Donald, Steven, and Paul working together = 1

∴ the number of days required to finish the whole work (1 work) by Donald + Steven + Paul together

= 1/3071/32736

= 1 × 32736/3071 = 32736/3071 days

= 10 2026/3071 days = or 10.66 days

Thus, Donald, Steven, and Paul working together will finish the total work (1 work) in 10 2026/3071 days = or 10.66 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 Donald = 31 days

And the number of days required to finish the same work by Steven = 32 days

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

Thus, the number of days required to finish the work by Donald, Steven, and Paul together = ?

Here a = 31 days

And, b = 32 days

And, c = 33 days

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

The number of days required to finish the work when Donald, Steven, and Paul working together

= 31 × 32 × 33/31 × 32 + 31 × 33 + 32 × 33 days

= 32736/992 + 1023 + 1056 days

= 32736/3071 days

= 32736/3071 days

= 10 2026/3071 days or 10.66

Thus, Donald, Steven, and Paul together will finish the work in 10 2026/3071 days or 10.66 days Answer


Similar Questions

(1) Charles can finish a work in 23 days. Daniel can finish the same work in 28 days while Matthew can finish the work in 33 days. How long will it take to finish it if they work together?

(2) If Daniel can finish the work in 24 days and Timothy can finish the same work in 27 days, then in how many days both can finish the work together?

(3) If Kimberly can finish the work in 35 days and Stephen can finish the same work in 38 days, then in how many days both can finish the work together?

(4) Alexander can finish a work in 91 days. Patrick can finish the same work in 96 days while Raymond can finish the work in 101 days. How long will it take to finish it if they work together?

(5) Jonathan can finish a work in 73 days. Larry can finish the same work in 78 days while Justin can finish the work in 83 days. How long will it take to finish it if they work together?

(6) If Samuel can finish the work in 87 days and Albert can finish the same work in 92 days, then in how many days both can finish the work together?

(7) If Linda can finish the work in 9 days and Charles can finish the same work in 12 days, then in how many days both can finish the work together?

(8) 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?

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(10) If Matthew can finish the work in 26 days and Edward can finish the same work in 29 days, then in how many days both can finish the work together?


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