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

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(2) Michelle can finish a work in 40 days. Carol can finish the same work in 41 days while Amanda can finish the work in 42 days. How long will it take to finish it if they work together?

(3) If William can finish the work in 12 days and Matthew can finish the same work in 16 days, then in how many days both can finish the work together?

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(6) James can finish a work in 5 days. John can finish the same work in 10 days while Michael can finish the work in 15 days. How long will it take to finish it if they work together?

(7) If Susan can finish the work in 15 days and Donald can finish the same work in 19 days, then in how many days both can finish the work together?

(8) Joshua can finish a work in 39 days. Kenneth can finish the same work in 40 days while Kevin can finish the work in 41 days. How long will it take to finish it if they work together?

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