Time and Work
MCQs Math


Question:     If Jason can finish the work in 59 days and Douglas can finish the same work in 64 days, then in how many days both can finish the work together?


Correct Answer  30 86/123 days or 30.699 days

Solution And Explanation

Solution

Given,

The number of days to finish the work by Jason = 59 days

And, the number of days to finish the same work by Douglas = 64 days

Thus, the number of days to finish the work by Jason and Douglas together = ?

Here,

∵ In 59 days the work done by Jason = 1

∴ In 1 day, the work done by Jason = 1/59 part

Similarly,

∵ In 64 days the work done by Douglas = 1

∴ In 1 day, the work done by Douglas = 1/64 part

Now, in 1 day, the work done by Jason and Douglas together

= In 1 day work done by Jason + In 1 day the work done by Douglas

= 1/59 + 1/64

= 64 + 59/3776

= 123/3776 part of work

This means in 1 day, 123/3776 part of work is done by Jason and Douglas working together.

Now, the number of days required to finish 123/3776 part of work by Jason + Douglas working together = 1

∴ the number of days required to finish 1 work by Jason + Douglas together

= 1/123/3776

= 1 × 3776/123 = 3776/123 days

= 30 86/123 days = or 30.699 days

Thus, Jason and Douglas working together will finish the work in 30 86/123 days = or 30.699 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 Jason = 59 days

And the number of days required to finish the same work by Douglas = 64 days

Thus, the number of days required to finish the work Jason and Douglas working together = ?

Here a = 59 days

And, b = 64 days

Thus, using formula a × b/a + b days

The number of days required to finish the work when Jason and Douglas working together

= 59 × 64/59 + 64 days

= 3776/123 days

= 30 86/123 days or 30.699

Thus, Jason and Douglas together will finish the work in 30 86/123 days or 30.699 days Answer


Similar Questions

(1) John can finish a work in 9 days. David can finish the same work in 14 days while William can finish the work in 19 days. How long will it take to finish it if they work together?

(2) If Patricia can finish the work in 5 days and William can finish the same work in 8 days, then in how many days both can finish the work together?

(3) Karen can finish a work in 20 days. Lisa can finish the same work in 21 days while Nancy can finish the work in 22 days. How long will it take to finish it if they work together?

(4) Pamela can finish a work in 78 days. Nicole can finish the same work in 83 days while Helen can finish the work in 88 days. How long will it take to finish it if they work together?

(5) If Elizabeth can finish the work in 11 days and Daniel can finish the same work in 15 days, then in how many days both can finish the work together?

(6) If Sarah can finish the work in 22 days and Joshua can finish the same work in 27 days, then in how many days both can finish the work together?

(7) Jessica can finish a work in 16 days. Sarah can finish the same work in 17 days while Karen can finish the work in 18 days. How long will it take to finish it if they work together?

(8) If Rachel can finish the work in 94 days and Roy can finish the same work in 99 days, then in how many days both can finish the work together?

(9) If Ashley can finish the work in 33 days and Eric can finish the same work in 36 days, then in how many days both can finish the work together?

(10) Jeffrey can finish a work in 61 days. Jacob can finish the same work in 66 days while Gary can finish the work in 71 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. ©