Time and Work
MCQs Math


Question:     If Kathleen can finish the work in 66 days and Jeremy can finish the same work in 71 days, then in how many days both can finish the work together?


Correct Answer  34 28/137 days or 34.204 days

Solution And Explanation

Solution

Given,

The number of days to finish the work by Kathleen = 66 days

And, the number of days to finish the same work by Jeremy = 71 days

Thus, the number of days to finish the work by Kathleen and Jeremy together = ?

Here,

∵ In 66 days the work done by Kathleen = 1

∴ In 1 day, the work done by Kathleen = 1/66 part

Similarly,

∵ In 71 days the work done by Jeremy = 1

∴ In 1 day, the work done by Jeremy = 1/71 part

Now, in 1 day, the work done by Kathleen and Jeremy together

= In 1 day work done by Kathleen + In 1 day the work done by Jeremy

= 1/66 + 1/71

= 71 + 66/4686

= 137/4686 part of work

This means in 1 day, 137/4686 part of work is done by Kathleen and Jeremy working together.

Now, the number of days required to finish 137/4686 part of work by Kathleen + Jeremy working together = 1

∴ the number of days required to finish 1 work by Kathleen + Jeremy together

= 1/137/4686

= 1 × 4686/137 = 4686/137 days

= 34 28/137 days = or 34.204 days

Thus, Kathleen and Jeremy working together will finish the work in 34 28/137 days = or 34.204 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 required to finish the work by Kathleen = 66 days

And the number of days required to finish the same work by Jeremy = 71 days

Thus, the number of days required to finish the work Kathleen and Jeremy working together = ?

Here a = 66 days

And, b = 71 days

Thus, using formula a × b/a + b days

The number of days required to finish the work when Kathleen and Jeremy working together

= 66 × 71/66 + 71 days

= 4686/137 days

= 34 28/137 days or 34.204

Thus, Kathleen and Jeremy together will finish the work in 34 28/137 days or 34.204 days Answer


Similar Questions

(1) If Carol can finish the work in 46 days and Alexander can finish the same work in 51 days, then in how many days both can finish the work together?

(2) If Frank can finish the work in 93 days and Randy can finish the same work in 98 days, then in how many days both can finish the work together?

(3) If Donald can finish the work in 32 days and Nicholas can finish the same work in 35 days, then in how many days both can finish the work together?

(4) 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?

(5) If Robert can finish a work in 5 days and Bob can finish the same work in 6 days, then in how many days they both can finish the work working together?

(6) If Catherine can finish the work in 100 days and Mason can finish the same work in 105 days, then in how many days both can finish the work together?

(7) 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?

(8) Cynthia can finish a work in 64 days. Amy can finish the same work in 69 days while Angela can finish the work in 74 days. How long will it take to finish it if they work together?

(9) If Nancy can finish the work in 28 days and Ronald can finish the same work in 33 days, then in how many days both can finish the work together?

(10) Margaret can finish a work in 32 days. Ashley can finish the same work in 37 days while Kimberly can finish the work in 42 days. How long will it take to finish it if they work together?


NCERT Solution and CBSE Notes for class twelve, eleventh, tenth, ninth, seventh, sixth, fifth, fourth and General Math for competitive Exams. ©