Time and Work
MCQs Math


Question:     Daniel can finish a work in 23 days. Matthew can finish the same work in 24 days while Anthony can finish the work in 25 days. How long will it take to finish it if they work together?


Correct Answer  7 1711/1727 days or 7.991 days

Solution And Explanation

Solution

Given,

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

And, the number of days required to finish the same work by Matthew = 24 days

And, the number of days required to finish the same work by Anthony = 25 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 Daniel = 1

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

Similarly,

∵ In 24 days the work is done by Matthew = 1

∴ The work done by Matthew in 1 day = 1/24

Similarly,

∵ In 25 days the work is done by Anthony = 1

∴ The work done by Anthony in 1 day = 1/25 part

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

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

= 1/23 + 1/24 + 1/25

= 600 + 575 + 552/13800

= 1727/13800 part of work

This means in 1 day, 1727/13800 part of work is done by Daniel, Matthew and Anthony working together.

Now, the number of days required to finish 1727/13800 part of work by Daniel, Matthew, and Anthony working together = 1

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

= 1/1727/13800

= 1 × 13800/1727 = 13800/1727 days

= 7 1711/1727 days = or 7.991 days

Thus, Daniel, Matthew, and Anthony working together will finish the total work (1 work) in 7 1711/1727 days = or 7.991 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 Daniel = 23 days

And the number of days required to finish the same work by Matthew = 24 days

And the number of days required to finish the work by Anthony = 25 days

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

Here a = 23 days

And, b = 24 days

And, c = 25 days

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

The number of days required to finish the work when Daniel, Matthew, and Anthony working together

= 23 × 24 × 25/23 × 24 + 23 × 25 + 24 × 25 days

= 13800/552 + 575 + 600 days

= 13800/1727 days

= 13800/1727 days

= 7 1711/1727 days or 7.991

Thus, Daniel, Matthew, and Anthony together will finish the work in 7 1711/1727 days or 7.991 days Answer


Similar Questions

(1) If Michelle can finish the work in 41 days and Samuel can finish the same work in 44 days, then in how many days both can finish the work together?

(2) If Emily can finish the work in 37 days and Justin can finish the same work in 41 days, then in how many days both can finish the work together?

(3) 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?

(4) If Mary can finish the work in 25 days and Michael can finish the same work in 41 days, then in how many days both can finish the work together?

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(6) Jessica can finish a work in 16 days. Sarah can finish the same work in 17 days while Karen can finish the work in 18 days. How long will it take to finish it if they work together?

(7) Steven can finish a work in 37 days. Andrew can finish the same work in 42 days while Joshua can finish the work in 47 days. How long will it take to finish it if they work together?

(8) If Charles can finish the work in 20 days and Kenneth can finish the same work in 23 days, then in how many days both can finish the work together?

(9) Dorothy can finish a work in 46 days. Melissa can finish the same work in 47 days while Deborah can finish the work in 48 days. How long will it take to finish it if they work together?

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