Time and Work
MCQs Math


Question:     Gary can finish a work in 67 days. Eric can finish the same work in 72 days while Jonathan can finish the work in 77 days. How long will it take to finish it if they work together?


Correct Answer  23 14327/15527 days or 23.923 days

Solution And Explanation

Solution

Given,

The number of days required to finish a piece of work by Gary = 67 days

And, the number of days required to finish the same work by Eric = 72 days

And, the number of days required to finish the same work by Jonathan = 77 days

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

Here,

∵ In 67 days the work is done by Gary = 1

∴ The work done by Gary in 1 day = 1/67

Similarly,

∵ In 72 days the work is done by Eric = 1

∴ The work done by Eric in 1 day = 1/72

Similarly,

∵ In 77 days the work is done by Jonathan = 1

∴ The work done by Jonathan in 1 day = 1/77 part

Now, the work done by Gary, Eric, and Jonathan together in 1 day

= Gary's 1 day work + Eric's 1 day work + Jonathan's 1 day work

= 1/67 + 1/72 + 1/77

= 5544 + 5159 + 4824/371448

= 15527/371448 part of work

This means in 1 day, 15527/371448 part of work is done by Gary, Eric and Jonathan working together.

Now, the number of days required to finish 15527/371448 part of work by Gary, Eric, and Jonathan working together = 1

∴ the number of days required to finish the whole work (1 work) by Gary + Eric + Jonathan together

= 1/15527/371448

= 1 × 371448/15527 = 371448/15527 days

= 23 14327/15527 days = or 23.923 days

Thus, Gary, Eric, and Jonathan working together will finish the total work (1 work) in 23 14327/15527 days = or 23.923 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 Gary = 67 days

And the number of days required to finish the same work by Eric = 72 days

And the number of days required to finish the work by Jonathan = 77 days

Thus, the number of days required to finish the work by Gary, Eric, and Jonathan together = ?

Here a = 67 days

And, b = 72 days

And, c = 77 days

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

The number of days required to finish the work when Gary, Eric, and Jonathan working together

= 67 × 72 × 77/67 × 72 + 67 × 77 + 72 × 77 days

= 371448/4824 + 5159 + 5544 days

= 371448/15527 days

= 371448/15527 days

= 23 14327/15527 days or 23.923

Thus, Gary, Eric, and Jonathan together will finish the work in 23 14327/15527 days or 23.923 days Answer


Similar Questions

(1) 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?

(2) If Edward can finish the work in 57 days and Nathan can finish the same work in 62 days, then in how many days both can finish the work together?

(3) If A can finish a work in 10 days and B can finish the same work in 15 days, then in how many days they both can finish the work working together?

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(5) If Jacob can finish the work in 65 days and Noah can finish the same work in 70 days, then in how many days both can finish the work together?

(6) If Margaret can finish the work in 29 days and Ryan can finish the same work in 32 days, then in how many days both can finish the work together?

(7) If George can finish the work in 51 days and Dennis can finish the same work in 56 days, then in how many days both can finish the work together?

(8) 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?

(9) William can finish a work in 11 days. Richard can finish the same work in 12 days while Joseph can finish the work in 13 days. How long will it take to finish it if they work together?

(10) 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?


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