Time and Work
MCQs Math


Question:     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?


Correct Answer  19 53/79 days or 19.671 days

Solution And Explanation

Solution

Given,

The number of days to finish the work by Steven = 37 days

And, the number of days to finish the same work by Jonathan = 42 days

Thus, the number of days to finish the work by Steven and Jonathan together = ?

Here,

∵ In 37 days the work done by Steven = 1

∴ In 1 day, the work done by Steven = 1/37 part

Similarly,

∵ In 42 days the work done by Jonathan = 1

∴ In 1 day, the work done by Jonathan = 1/42 part

Now, in 1 day, the work done by Steven and Jonathan together

= In 1 day work done by Steven + In 1 day the work done by Jonathan

= 1/37 + 1/42

= 42 + 37/1554

= 79/1554 part of work

This means in 1 day, 79/1554 part of work is done by Steven and Jonathan working together.

Now, the number of days required to finish 79/1554 part of work by Steven + Jonathan working together = 1

∴ the number of days required to finish 1 work by Steven + Jonathan together

= 1/79/1554

= 1 × 1554/79 = 1554/79 days

= 19 53/79 days = or 19.671 days

Thus, Steven and Jonathan working together will finish the work in 19 53/79 days = or 19.671 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 Steven = 37 days

And the number of days required to finish the same work by Jonathan = 42 days

Thus, the number of days required to finish the work Steven and Jonathan working together = ?

Here a = 37 days

And, b = 42 days

Thus, using formula a × b/a + b days

The number of days required to finish the work when Steven and Jonathan working together

= 37 × 42/37 + 42 days

= 1554/79 days

= 19 53/79 days or 19.671

Thus, Steven and Jonathan together will finish the work in 19 53/79 days or 19.671 days Answer


Similar Questions

(1) Gary can finish a work in 67 days. Eric can finish the same work in 72 days while Jonathan can finish the work in 77 days. How long will it take to finish it if they work together?

(2) If Richard can finish the work in 14 days and Mark can finish the same work in 18 days, then in how many days both can finish the work together?

(3) If Stephanie can finish the work in 56 days and Adam can finish the same work in 61 days, then in how many days both can finish the work together?

(4) 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?

(5) Daniel can finish a work in 23 days. Matthew can finish the same work in 24 days while Anthony can finish the work in 25 days. How long will it take to finish it if they work together?

(6) George can finish a work in 51 days. Ronald can finish the same work in 56 days while Edward can finish the work in 61 days. How long will it take to finish it if they work together?

(7) If Mary can finish the work in 3 days and Michael can finish the same work in 7 days, then in how many days both can finish the work together?

(8) If Linda can finish the work in 9 days and Charles can finish the same work in 12 days, then in how many days both can finish the work together?

(9) Elizabeth can finish a work in 10 days. Barbara can finish the same work in 11 days while Susan can finish the work in 12 days. How long will it take to finish it if they work together?

(10) If Elizabeth can finish the work in 11 days and Daniel can finish the same work in 14 days, then in how many days both can finish the work together?


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