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) Karen can finish a work in 24 days. Nancy can finish the same work in 29 days while Betty can finish the work in 34 days. How long will it take to finish it if they work together?

(2) If Betty can finish the work in 27 days and Jason can finish the same work in 30 days, then in how many days both can finish the work together?

(3) Catherine can finish a work in 100 days. Heather can finish the same work in 105 days while Diane can finish the work in 110 days. How long will it take to finish it if they work together?

(4) If Anna can finish the work in 74 days and Austin can finish the same work in 79 days, then in how many days both can finish the work together?

(5) If Myra can finish the work in 15 days and Sophia can finish the same work in 20 days, then in how many days they both can finish the work working together?

(6) If George can finish the work in 51 days and Dennis can finish the same work in 56 days, then in how many days both can finish the work together?

(7) Anthony can finish a work in 31 days. Donald can finish the same work in 36 days while Steven can finish the work in 41 days. How long will it take to finish it if they work together?

(8) George can finish a work in 51 days. Ronald can finish the same work in 56 days while Edward can finish the work in 61 days. How long will it take to finish it if they work together?

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

(10) If Kevin can finish the work in 44 days and Frank can finish the same work in 47 days, then in how many days both can finish the work together?


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