Time and Work
MCQs Math


Question:     If Steven can finish the work in 34 days and Jonathan can finish the same work in 38 days, then in how many days both can finish the work together?


Correct Answer  17 17/18 days or 17.944 days

Solution And Explanation

Solution

Given,

The number of days to finish the work by Steven = 34 days

And, the number of days to finish the same work by Jonathan = 38 days

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

Here,

∵ In 34 days the work done by Steven = 1

∴ In 1 day, the work done by Steven = 1/34 part

Similarly,

∵ In 38 days the work done by Jonathan = 1

∴ In 1 day, the work done by Jonathan = 1/38 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

= 1/34 + 1/38

= 19 + 17/646

= 36/646 part of work

= 36 ÷ 2/646 ÷ 2 part of work

= 18/323 part of work

This means, in 1 day, 18/323 part of the work is done by Steven and Jonathan together.

Now, the number of days required to finish 18/323 part of work by Steven + Jonathan working together = 1

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

= 1/18/323

= 1 × 323/18 = 323/18 days

= 17 17/18 days = or 17.944 days

Thus, Steven and Jonathan working together will finish the work in 17 17/18 days = or 17.944 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 = 34 days

And the number of days required to finish the same work by Jonathan = 38 days

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

Here a = 34 days

And, b = 38 days

Thus, using formula a × b/a + b days

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

= 34 × 38/34 + 38 days

= 1292/72 days

= 1292 ÷ 4/72 ÷ 4 = 323/18 days

= 17 17/18 days or 17.944

Thus, Steven and Jonathan together will finish the work in 17 17/18 days or 17.944 days Answer


Similar Questions

(1) Janet can finish a work in 98 days. Maria can finish the same work in 103 days while Heather can finish the work in 108 days. How long will it take to finish it if they work together?

(2) 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?

(3) If Brian can finish the work in 46 days and Raymond can finish the same work in 49 days, then in how many days both can finish the work together?

(4) Charles can finish a work in 19 days. Christopher can finish the same work in 20 days while Daniel can finish the work in 21 days. How long will it take to finish it if they work together?

(5) If Andrew can finish the work in 41 days and Scott can finish the same work in 46 days, then in how many days both can finish the work together?

(6) 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?

(7) If Sandra can finish the work in 34 days and Gary can finish the same work in 39 days, then in how many days both can finish the work together?

(8) Patricia can finish a work in 4 days. Jennifer can finish the same work in 5 days while Linda can finish the work in 6 days. How long will it take to finish it if they work together?

(9) 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?

(10) William can finish a work in 15 days. Joseph can finish the same work in 20 days while Thomas can finish the work in 25 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. ©