Time and Work
MCQs Math


Question:     Amanda can finish a work in 44 days. Dorothy can finish the same work in 45 days while Melissa can finish the work in 46 days. How long will it take to finish it if they work together?


Correct Answer  14 3022/3037 days or 14.995 days

Solution And Explanation

Solution

Given,

The number of days required to finish a piece of work by Amanda = 44 days

And, the number of days required to finish the same work by Dorothy = 45 days

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

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

Here,

∵ In 44 days the work is done by Amanda = 1

∴ The work done by Amanda in 1 day = 1/44

Similarly,

∵ In 45 days the work is done by Dorothy = 1

∴ The work done by Dorothy in 1 day = 1/45

Similarly,

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

∴ The work done by Melissa in 1 day = 1/46 part

Now, the work done by Amanda, Dorothy, and Melissa together in 1 day

= Amanda's 1 day work + Dorothy's 1 day work + Melissa's 1 day work

= 1/44 + 1/45 + 1/46

= 1035 + 1012 + 990/45540

= 3037/45540 part of work

This means in 1 day, 3037/45540 part of work is done by Amanda, Dorothy and Melissa working together.

Now, the number of days required to finish 3037/45540 part of work by Amanda, Dorothy, and Melissa working together = 1

∴ the number of days required to finish the whole work (1 work) by Amanda + Dorothy + Melissa together

= 1/3037/45540

= 1 × 45540/3037 = 45540/3037 days

= 14 3022/3037 days = or 14.995 days

Thus, Amanda, Dorothy, and Melissa working together will finish the total work (1 work) in 14 3022/3037 days = or 14.995 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 Amanda = 44 days

And the number of days required to finish the same work by Dorothy = 45 days

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

Thus, the number of days required to finish the work by Amanda, Dorothy, and Melissa together = ?

Here a = 44 days

And, b = 45 days

And, c = 46 days

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

The number of days required to finish the work when Amanda, Dorothy, and Melissa working together

= 44 × 45 × 46/44 × 45 + 44 × 46 + 45 × 46 days

= 91080/1980 + 2024 + 2070 days

= 91080/6074 days

= 91080/6074 days

= 91080 ÷ 2/6074 ÷ 2 = 45540/3037 days

= 14 3022/3037 days or 14.995

Thus, Amanda, Dorothy, and Melissa together will finish the work in 14 3022/3037 days or 14.995 days Answer


Similar Questions

(1) 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?

(2) Donna can finish a work in 42 days. Carol can finish the same work in 47 days while Amanda can finish the work in 52 days. How long will it take to finish it if they work together?

(3) If Thomas can finish the work in 21 days and Andrew can finish the same work in 26 days, then in how many days both can finish the work together?

(4) Jennifer can finish a work in 6 days. Linda can finish the same work in 7 days while Elizabeth can finish the work in 8 days. How long will it take to finish it if they work together?

(5) If Jessica can finish the work in 17 days and Paul can finish the same work in 21 days, then in how many days both can finish the work together?

(6) If Michelle can finish the work in 41 days and Samuel can finish the same work in 45 days, then in how many days both can finish the work together?

(7) Kathleen can finish a work in 66 days. Angela can finish the same work in 71 days while Shirley can finish the work in 76 days. How long will it take to finish it if they work together?

(8) If Robert can finish the work in 7 days and David can finish the same work in 12 days, then in how many days both can finish the work together?

(9) Deborah can finish a work in 54 days. Rebecca can finish the same work in 59 days while Sharon can finish the work in 64 days. How long will it take to finish it if they work together?

(10) If Jeffrey can finish the work in 61 days and Peter can finish the same work in 66 days, then in how many days both can finish the work together?


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