Time and Work
MCQs Math


Question:     If Joshua can finish the work in 40 days and Benjamin can finish the same work in 44 days, then in how many days both can finish the work together?


Correct Answer  20 20/21 days or 20.952 days

Solution And Explanation

Solution

Given,

The number of days to finish the work by Joshua = 40 days

And, the number of days to finish the same work by Benjamin = 44 days

Thus, the number of days to finish the work by Joshua and Benjamin together = ?

Here,

∵ In 40 days the work done by Joshua = 1

∴ In 1 day, the work done by Joshua = 1/40 part

Similarly,

∵ In 44 days the work done by Benjamin = 1

∴ In 1 day, the work done by Benjamin = 1/44 part

Now, in 1 day, the work done by Joshua and Benjamin together

= In 1 day work done by Joshua + In 1 day the work done by Benjamin

= 1/40 + 1/44

= 11 + 10/440

= 21/440 part of work

This means in 1 day, 21/440 part of work is done by Joshua and Benjamin working together.

Now, the number of days required to finish 21/440 part of work by Joshua + Benjamin working together = 1

∴ the number of days required to finish 1 work by Joshua + Benjamin together

= 1/21/440

= 1 × 440/21 = 440/21 days

= 20 20/21 days = or 20.952 days

Thus, Joshua and Benjamin working together will finish the work in 20 20/21 days = or 20.952 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 Joshua = 40 days

And the number of days required to finish the same work by Benjamin = 44 days

Thus, the number of days required to finish the work Joshua and Benjamin working together = ?

Here a = 40 days

And, b = 44 days

Thus, using formula a × b/a + b days

The number of days required to finish the work when Joshua and Benjamin working together

= 40 × 44/40 + 44 days

= 1760/84 days

= 1760 ÷ 4/84 ÷ 4 = 440/21 days

= 20 20/21 days or 20.952

Thus, Joshua and Benjamin together will finish the work in 20 20/21 days or 20.952 days Answer


Similar Questions

(1) If John can finish the work in 28 days and Richard can finish the same work in 44 days, then in how many days both can finish the work together?

(2) Sarah can finish a work in 18 days. Karen can finish the same work in 19 days while Lisa can finish the work in 20 days. How long will it take to finish it if they work together?

(3) Eric can finish a work in 71 days. Stephen can finish the same work in 76 days while Larry can finish the work in 81 days. How long will it take to finish it if they work together?

(4) If James can finish the work in 24 days and John can finish the same work in 40 days, then in how many days both can finish the work together?

(5) If Michelle can finish the work in 44 days and Samuel can finish the same work in 49 days, then in how many days both can finish the work together?

(6) If Annie can finish a work in 2 days and Bobby can finish the same work in 3 days, then in how many days they both can finish the work working together?

(7) Angela can finish a work in 70 days. Anna can finish the same work in 75 days while Brenda can finish the work in 80 days. How long will it take to finish it if they work together?

(8) If Gary can finish the work in 67 days and Christian can finish the same work in 72 days, then in how many days both can finish the work together?

(9) If John can finish the work in 6 days and Richard can finish the same work in 9 days, then in how many days both can finish the work together?

(10) If Amanda can finish the work in 45 days and Patrick can finish the same work in 48 days, then in how many days both can finish the work together?


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