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) If Eric can finish the work in 71 days and Gerald can finish the same work in 76 days, then in how many days both can finish the work together?

(2) 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?

(3) If Scott can finish the work in 81 days and Bryan can finish the same work in 86 days, then in how many days both can finish the work together?

(4) If Joshua can finish the work in 40 days and Benjamin can finish the same work in 43 days, then in how many days both can finish the work together?

(5) Stephen can finish a work in 75 days. Justin can finish the same work in 80 days while Scott can finish the work in 85 days. How long will it take to finish it if they work together?

(6) Anthony can finish a work in 31 days. Donald can finish the same work in 36 days while Steven can finish the work in 41 days. How long will it take to finish it if they work together?

(7) Christopher can finish a work in 25 days. Matthew can finish the same work in 30 days while Anthony can finish the work in 35 days. How long will it take to finish it if they work together?

(8) Patricia can finish a work in 8 days. Linda can finish the same work in 13 days while Elizabeth can finish the work in 18 days. How long will it take to finish it if they work together?

(9) If Betty can finish the work in 27 days and Jason can finish the same work in 31 days, then in how many days both can finish the work together?

(10) If Paul can finish the work in 36 days and Larry can finish the same work in 40 days, then in how many days both can finish the work together?


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