Time and Work
MCQs Math


Question:     Kevin can finish a work in 47 days. George can finish the same work in 52 days while Timothy can finish the work in 57 days. How long will it take to finish it if they work together?


Correct Answer  17 1829/8087 days or 17.226 days

Solution And Explanation

Solution

Given,

The number of days required to finish a piece of work by Kevin = 47 days

And, the number of days required to finish the same work by George = 52 days

And, the number of days required to finish the same work by Timothy = 57 days

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

Here,

∵ In 47 days the work is done by Kevin = 1

∴ The work done by Kevin in 1 day = 1/47

Similarly,

∵ In 52 days the work is done by George = 1

∴ The work done by George in 1 day = 1/52

Similarly,

∵ In 57 days the work is done by Timothy = 1

∴ The work done by Timothy in 1 day = 1/57 part

Now, the work done by Kevin, George, and Timothy together in 1 day

= Kevin's 1 day work + George's 1 day work + Timothy's 1 day work

= 1/47 + 1/52 + 1/57

= 2964 + 2679 + 2444/139308

= 8087/139308 part of work

This means in 1 day, 8087/139308 part of work is done by Kevin, George and Timothy working together.

Now, the number of days required to finish 8087/139308 part of work by Kevin, George, and Timothy working together = 1

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

= 1/8087/139308

= 1 × 139308/8087 = 139308/8087 days

= 17 1829/8087 days = or 17.226 days

Thus, Kevin, George, and Timothy working together will finish the total work (1 work) in 17 1829/8087 days = or 17.226 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 Kevin = 47 days

And the number of days required to finish the same work by George = 52 days

And the number of days required to finish the work by Timothy = 57 days

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

Here a = 47 days

And, b = 52 days

And, c = 57 days

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

The number of days required to finish the work when Kevin, George, and Timothy working together

= 47 × 52 × 57/47 × 52 + 47 × 57 + 52 × 57 days

= 139308/2444 + 2679 + 2964 days

= 139308/8087 days

= 139308/8087 days

= 17 1829/8087 days or 17.226

Thus, Kevin, George, and Timothy together will finish the work in 17 1829/8087 days or 17.226 days Answer


Similar Questions

(1) If Brian can finish the work in 46 days and Raymond can finish the same work in 49 days, then in how many days both can finish the work together?

(2) Ashley can finish a work in 36 days. Emily can finish the same work in 41 days while Donna can finish the work in 46 days. How long will it take to finish it if they work together?

(3) If Betty can finish the work in 27 days and Jason can finish the same work in 30 days, then in how many days both can finish the work together?

(4) Debra can finish a work in 92 days. Carolyn can finish the same work in 97 days while Janet can finish the work in 102 days. How long will it take to finish it if they work together?

(5) If Susan can finish the work in 15 days and Donald can finish the same work in 18 days, then in how many days both can finish the work together?

(6) 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?

(7) If Patricia can finish the work in 8 days and William can finish the same work in 13 days, then in how many days both can finish the work together?

(8) Amanda can finish a work in 48 days. Melissa can finish the same work in 53 days while Deborah can finish the work in 58 days. How long will it take to finish it if they work together?

(9) Janet can finish a work in 98 days. Maria can finish the same work in 103 days while Heather can finish the work in 108 days. How long will it take to finish it if they work together?

(10) If Annie can finish a work in 3 days and Bobby can finish the same work in 6 days, then in how many days they both can finish the work working together?


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