Time and Work
MCQs Math


Question:     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?


Correct Answer  23 69/95 days or 23.726 days

Solution And Explanation

Solution

Given,

The number of days to finish the work by Brian = 46 days

And, the number of days to finish the same work by Raymond = 49 days

Thus, the number of days to finish the work by Brian and Raymond together = ?

Here,

∵ In 46 days the work done by Brian = 1

∴ In 1 day, the work done by Brian = 1/46 part

Similarly,

∵ In 49 days the work done by Raymond = 1

∴ In 1 day, the work done by Raymond = 1/49 part

Now, in 1 day, the work done by Brian and Raymond together

= In 1 day work done by Brian + In 1 day the work done by Raymond

= 1/46 + 1/49

= 49 + 46/2254

= 95/2254 part of work

This means in 1 day, 95/2254 part of work is done by Brian and Raymond working together.

Now, the number of days required to finish 95/2254 part of work by Brian + Raymond working together = 1

∴ the number of days required to finish 1 work by Brian + Raymond together

= 1/95/2254

= 1 × 2254/95 = 2254/95 days

= 23 69/95 days = or 23.726 days

Thus, Brian and Raymond working together will finish the work in 23 69/95 days = or 23.726 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 Brian = 46 days

And the number of days required to finish the same work by Raymond = 49 days

Thus, the number of days required to finish the work Brian and Raymond working together = ?

Here a = 46 days

And, b = 49 days

Thus, using formula a × b/a + b days

The number of days required to finish the work when Brian and Raymond working together

= 46 × 49/46 + 49 days

= 2254/95 days

= 23 69/95 days or 23.726

Thus, Brian and Raymond together will finish the work in 23 69/95 days or 23.726 days Answer


Similar Questions

(1) If Sandra can finish the work in 31 days and Gary can finish the same work in 35 days, then in how many days both can finish the work together?

(2) If Michelle can finish the work in 41 days and Samuel can finish the same work in 45 days, then in how many days both can finish the work together?

(3) If Justin can finish the work in 79 days and Jesse can finish the same work in 84 days, then in how many days both can finish the work together?

(4) Betty can finish a work in 30 days. Sandra can finish the same work in 35 days while Ashley can finish the work in 40 days. How long will it take to finish it if they work together?

(5) If David can finish the work in 10 days and Christopher can finish the same work in 14 days, then in how many days both can finish the work together?

(6) Larry can finish a work in 77 days. Scott can finish the same work in 82 days while Brandon can finish the work in 87 days. How long will it take to finish it if they work together?

(7) If A can do a piece of work in 2 days, B can do the same piece of work in 3 days, while C alone can do the same work in 4 days. Find the number of days to finish the work when they all will work together.

(8) Michael can finish a work in 7 days. David can finish the same work in 8 days while William can finish the work in 9 days. How long will it take to finish it if they work together?

(9) If Christopher can finish the work in 22 days and Brian can finish the same work in 25 days, then in how many days both can finish the work together?

(10) Ashley can finish a work in 36 days. Emily can finish the same work in 41 days while Donna can finish the work in 46 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. ©