Time and Work
MCQs Math


Question:     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?


Correct Answer  9 309/2327 days or 9.133 days

Solution And Explanation

Solution

Given,

The number of days required to finish a piece of work by Charles = 23 days

And, the number of days required to finish the same work by Daniel = 28 days

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

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

Here,

∵ In 23 days the work is done by Charles = 1

∴ The work done by Charles in 1 day = 1/23

Similarly,

∵ In 28 days the work is done by Daniel = 1

∴ The work done by Daniel in 1 day = 1/28

Similarly,

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

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

Now, the work done by Charles, Daniel, and Matthew together in 1 day

= Charles's 1 day work + Daniel's 1 day work + Matthew's 1 day work

= 1/23 + 1/28 + 1/33

= 924 + 759 + 644/21252

= 2327/21252 part of work

This means in 1 day, 2327/21252 part of work is done by Charles, Daniel and Matthew working together.

Now, the number of days required to finish 2327/21252 part of work by Charles, Daniel, and Matthew working together = 1

∴ the number of days required to finish the whole work (1 work) by Charles + Daniel + Matthew together

= 1/2327/21252

= 1 × 21252/2327 = 21252/2327 days

= 9 309/2327 days = or 9.133 days

Thus, Charles, Daniel, and Matthew working together will finish the total work (1 work) in 9 309/2327 days = or 9.133 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 Charles = 23 days

And the number of days required to finish the same work by Daniel = 28 days

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

Thus, the number of days required to finish the work by Charles, Daniel, and Matthew together = ?

Here a = 23 days

And, b = 28 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 Charles, Daniel, and Matthew working together

= 23 × 28 × 33/23 × 28 + 23 × 33 + 28 × 33 days

= 21252/644 + 759 + 924 days

= 21252/2327 days

= 21252/2327 days

= 9 309/2327 days or 9.133

Thus, Charles, Daniel, and Matthew together will finish the work in 9 309/2327 days or 9.133 days Answer


Similar Questions

(1) If Anthony can finish the work in 28 days and Jeffrey can finish the same work in 32 days, then in how many days both can finish the work together?

(2) If William can finish the work in 12 days and Matthew can finish the same work in 15 days, then in how many days both can finish the work together?

(3) If Annie can finish a work in 5 days and Bobby can finish the same work in 10 days, then in how many days they both can finish the work working together?

(4) If Daniel can finish the work in 27 days and Timothy can finish the same work in 32 days, then in how many days both can finish the work together?

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(6) Jeffrey can finish a work in 61 days. Jacob can finish the same work in 66 days while Gary can finish the work in 71 days. How long will it take to finish it if they work together?

(7) If David can finish the work in 10 days and Christopher can finish the same work in 14 days, then in how many days both can finish the work together?

(8) William can finish a work in 15 days. Joseph can finish the same work in 20 days while Thomas can finish the work in 25 days. How long will it take to finish it if they work together?

(9) 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?

(10) If Melissa can finish the work in 52 days and Jerry can finish the same work in 57 days, then in how many days both can finish the work together?


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