Time and Work
MCQs Math


Question:     Gregory can finish a work in 89 days. Frank can finish the same work in 94 days while Patrick can finish the work in 99 days. How long will it take to finish it if they work together?


Correct Answer  31 7261/26483 days or 31.274 days

Solution And Explanation

Solution

Given,

The number of days required to finish a piece of work by Gregory = 89 days

And, the number of days required to finish the same work by Frank = 94 days

And, the number of days required to finish the same work by Patrick = 99 days

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

Here,

∵ In 89 days the work is done by Gregory = 1

∴ The work done by Gregory in 1 day = 1/89

Similarly,

∵ In 94 days the work is done by Frank = 1

∴ The work done by Frank in 1 day = 1/94

Similarly,

∵ In 99 days the work is done by Patrick = 1

∴ The work done by Patrick in 1 day = 1/99 part

Now, the work done by Gregory, Frank, and Patrick together in 1 day

= Gregory's 1 day work + Frank's 1 day work + Patrick's 1 day work

= 1/89 + 1/94 + 1/99

= 9306 + 8811 + 8366/828234

= 26483/828234 part of work

This means in 1 day, 26483/828234 part of work is done by Gregory, Frank and Patrick working together.

Now, the number of days required to finish 26483/828234 part of work by Gregory, Frank, and Patrick working together = 1

∴ the number of days required to finish the whole work (1 work) by Gregory + Frank + Patrick together

= 1/26483/828234

= 1 × 828234/26483 = 828234/26483 days

= 31 7261/26483 days = or 31.274 days

Thus, Gregory, Frank, and Patrick working together will finish the total work (1 work) in 31 7261/26483 days = or 31.274 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 Gregory = 89 days

And the number of days required to finish the same work by Frank = 94 days

And the number of days required to finish the work by Patrick = 99 days

Thus, the number of days required to finish the work by Gregory, Frank, and Patrick together = ?

Here a = 89 days

And, b = 94 days

And, c = 99 days

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

The number of days required to finish the work when Gregory, Frank, and Patrick working together

= 89 × 94 × 99/89 × 94 + 89 × 99 + 94 × 99 days

= 828234/8366 + 8811 + 9306 days

= 828234/26483 days

= 828234/26483 days

= 31 7261/26483 days or 31.274

Thus, Gregory, Frank, and Patrick together will finish the work in 31 7261/26483 days or 31.274 days Answer


Similar Questions

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(2) If Cynthia can finish the work in 64 days and Walter can finish the same work in 69 days, then in how many days both can finish the work together?

(3) Janet can finish a work in 98 days. Maria can finish the same work in 103 days while Heather can finish the work in 108 days. How long will it take to finish it if they work together?

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(6) Raymond can finish a work in 97 days. Dennis can finish the same work in 102 days while Jerry can finish the work in 107 days. How long will it take to finish it if they work together?

(7) 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?

(8) Barbara can finish a work in 16 days. Jessica can finish the same work in 21 days while Sarah can finish the work in 26 days. How long will it take to finish it if they work together?

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