Time and Work
MCQs Math


Question:     Andrew can finish a work in 41 days. Kenneth can finish the same work in 46 days while Kevin can finish the work in 51 days. How long will it take to finish it if they work together?


Correct Answer  15 1341/6323 days or 15.212 days

Solution And Explanation

Solution

Given,

The number of days required to finish a piece of work by Andrew = 41 days

And, the number of days required to finish the same work by Kenneth = 46 days

And, the number of days required to finish the same work by Kevin = 51 days

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

Here,

∵ In 41 days the work is done by Andrew = 1

∴ The work done by Andrew in 1 day = 1/41

Similarly,

∵ In 46 days the work is done by Kenneth = 1

∴ The work done by Kenneth in 1 day = 1/46

Similarly,

∵ In 51 days the work is done by Kevin = 1

∴ The work done by Kevin in 1 day = 1/51 part

Now, the work done by Andrew, Kenneth, and Kevin together in 1 day

= Andrew's 1 day work + Kenneth's 1 day work + Kevin's 1 day work

= 1/41 + 1/46 + 1/51

= 2346 + 2091 + 1886/96186

= 6323/96186 part of work

This means in 1 day, 6323/96186 part of work is done by Andrew, Kenneth and Kevin working together.

Now, the number of days required to finish 6323/96186 part of work by Andrew, Kenneth, and Kevin working together = 1

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

= 1/6323/96186

= 1 × 96186/6323 = 96186/6323 days

= 15 1341/6323 days = or 15.212 days

Thus, Andrew, Kenneth, and Kevin working together will finish the total work (1 work) in 15 1341/6323 days = or 15.212 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 Andrew = 41 days

And the number of days required to finish the same work by Kenneth = 46 days

And the number of days required to finish the work by Kevin = 51 days

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

Here a = 41 days

And, b = 46 days

And, c = 51 days

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

The number of days required to finish the work when Andrew, Kenneth, and Kevin working together

= 41 × 46 × 51/41 × 46 + 41 × 51 + 46 × 51 days

= 96186/1886 + 2091 + 2346 days

= 96186/6323 days

= 96186/6323 days

= 15 1341/6323 days or 15.212

Thus, Andrew, Kenneth, and Kevin together will finish the work in 15 1341/6323 days or 15.212 days Answer


Similar Questions

(1) If Annie can finish a work in 6 days and Bobby can finish the same work in 12 days, then in how many days they both can finish the work working together?

(2) If James can finish the work in 2 days and John can finish the same work in 6 days, then in how many days both can finish the work together?

(3) 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?

(4) If Kevin can finish the work in 47 days and Frank can finish the same work in 52 days, then in how many days both can finish the work together?

(5) If Andrew can finish the work in 41 days and Scott can finish the same work in 46 days, then in how many days both can finish the work together?

(6) If Donald can finish the work in 32 days and Nicholas can finish the same work in 35 days, then in how many days both can finish the work together?

(7) Richard can finish a work in 17 days. Thomas can finish the same work in 22 days while Charles can finish the work in 27 days. How long will it take to finish it if they work together?

(8) If Karen can finish the work in 24 days and Kevin can finish the same work in 29 days, then in how many days both can finish the work together?

(9) 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?

(10) Lisa can finish a work in 26 days. Betty can finish the same work in 31 days while Margaret can finish the work in 36 days. How long will it take to finish it if they work together?


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