Time and Work
MCQs Math


Question:     Paul can finish a work in 39 days. Joshua can finish the same work in 44 days while Kenneth can finish the work in 49 days. How long will it take to finish it if they work together?


Correct Answer  14 3122/5783 days or 14.54 days

Solution And Explanation

Solution

Given,

The number of days required to finish a piece of work by Paul = 39 days

And, the number of days required to finish the same work by Joshua = 44 days

And, the number of days required to finish the same work by Kenneth = 49 days

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

Here,

∵ In 39 days the work is done by Paul = 1

∴ The work done by Paul in 1 day = 1/39

Similarly,

∵ In 44 days the work is done by Joshua = 1

∴ The work done by Joshua in 1 day = 1/44

Similarly,

∵ In 49 days the work is done by Kenneth = 1

∴ The work done by Kenneth in 1 day = 1/49 part

Now, the work done by Paul, Joshua, and Kenneth together in 1 day

= Paul's 1 day work + Joshua's 1 day work + Kenneth's 1 day work

= 1/39 + 1/44 + 1/49

= 2156 + 1911 + 1716/84084

= 5783/84084 part of work

This means in 1 day, 5783/84084 part of work is done by Paul, Joshua and Kenneth working together.

Now, the number of days required to finish 5783/84084 part of work by Paul, Joshua, and Kenneth working together = 1

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

= 1/5783/84084

= 1 × 84084/5783 = 84084/5783 days

= 14 3122/5783 days = or 14.54 days

Thus, Paul, Joshua, and Kenneth working together will finish the total work (1 work) in 14 3122/5783 days = or 14.54 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 Paul = 39 days

And the number of days required to finish the same work by Joshua = 44 days

And the number of days required to finish the work by Kenneth = 49 days

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

Here a = 39 days

And, b = 44 days

And, c = 49 days

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

The number of days required to finish the work when Paul, Joshua, and Kenneth working together

= 39 × 44 × 49/39 × 44 + 39 × 49 + 44 × 49 days

= 84084/1716 + 1911 + 2156 days

= 84084/5783 days

= 84084/5783 days

= 14 3122/5783 days or 14.54

Thus, Paul, Joshua, and Kenneth together will finish the work in 14 3122/5783 days or 14.54 days Answer


Similar Questions

(1) If Barbara can finish the work in 35 days and Anthony can finish the same work in 51 days, then in how many days both can finish the work together?

(2) Patricia can finish a work in 8 days. Linda can finish the same work in 13 days while Elizabeth can finish the work in 18 days. How long will it take to finish it if they work together?

(3) Charles can finish a work in 19 days. Christopher can finish the same work in 20 days while Daniel can finish the work in 21 days. How long will it take to finish it if they work together?

(4) If Justin can finish the work in 79 days and Jesse can finish the same work in 84 days, then in how many days both can finish the work together?

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(6) If Nancy can finish the work in 28 days and Ronald can finish the same work in 33 days, then in how many days both can finish the work together?

(7) If Robert can finish the work in 26 days and David can finish the same work in 42 days, then in how many days both can finish the work together?

(8) Cynthia can finish a work in 64 days. Amy can finish the same work in 69 days while Angela can finish the work in 74 days. How long will it take to finish it if they work together?

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