Time and Work
MCQs Math


Question:     If Myra can finish the work in 25 days and Sophia can finish the same work in 15 days, then in how many days they both can finish the work working together?


Correct Answer  9 3/8 days or 9.375 days

Solution And Explanation

Solution

Given,

The number of days to finish the work by Myra = 25 days

And, the number of days to finish the same work by Sophia = 15 days

Thus, the number of days to finish the work by Myra and Sophia working together = ?

Here, ∵ In 25 days the work done by Myra = 1

∴ In 1 day, the work done by Myra = 1/25 part

Similarly, ∵ In 15 days the work done by Sophia = 1

∴ In 1 day, the work done by Sophia = 1/15 part

Now, in 1 day, the work done by Myra and Sophia working together

= In 1 day work done by Myra + In 1 day the work done by Sophia

= 1/25 + 1/15

= 3 + 5/75

= 8/75 part of work

This means in 1 day, 8/75 part of work is done by Myra and Sophia working together.

Now, the number of days required to finish 8/75 part of work by Myra + Sophia working together = 1

∴ the number of days required to finish 1 work by Myra + Sophia working together

= 1/8/75

= 1 × 75/8 = 75/8 days

= 93/8 days = 9.375 days

Thus, Myra and Sophia working together will finish the work in 93/8 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, and B can finish the same work in "b" days,
then working together the number of days require to finish the work
= a × b/a + b days.

Here given,

The number of days to finish the work by Myra = 25 days

And, the number of days to finish the same work by Sophia = 15 days

Thus, the number of days to finish the work by Myra and Sophia working together = ?

Here "a" = 25 days

And, "b" = 15 days

Thus, using formula a × b/a + b days

The number of days require to finish the work when Myra and Sophia working together

= 25 × 15/25 + 15 days

= 375/40 days

= 75 × 5/8 × 5 = 75/8 days

= 9 3/8 days or 9.375 days

Thus, Myra and Sophia working together will finish the work in 9 3/8 days or 9.375 days Answer


Similar Questions

(1) If Kevin can finish the work in 44 days and Frank can finish the same work in 48 days, then in how many days both can finish the work together?

(2) If Christopher can finish the work in 22 days and Brian can finish the same work in 26 days, then in how many days both can finish the work together?

(3) If Matthew can finish the work in 26 days and Edward can finish the same work in 30 days, then in how many days both can finish the work together?

(4) George can finish a work in 47 days. Timothy can finish the same work in 48 days while Ronald can finish the work in 49 days. How long will it take to finish it if they work together?

(5) Shirley can finish a work in 72 days. Brenda can finish the same work in 77 days while Pamela can finish the work in 82 days. How long will it take to finish it if they work together?

(6) If Brian can finish the work in 49 days and Raymond can finish the same work in 54 days, then in how many days both can finish the work together?

(7) If Melissa can finish the work in 49 days and Jerry can finish the same work in 52 days, then in how many days both can finish the work together?

(8) If Stephen can finish the work in 75 days and Carl can finish the same work in 80 days, then in how many days both can finish the work together?

(9) If Steven can finish the work in 37 days and Jonathan can finish the same work in 42 days, then in how many days both can finish the work together?

(10) Matthew can finish a work in 29 days. Mark can finish the same work in 34 days while Donald can finish the work in 39 days. How long will it take to finish it if they work together?


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