Time and Work
MCQs Math


Question:     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?


Correct Answer  21 59/87 days or 21.678 days

Solution And Explanation

Solution

Given,

The number of days to finish the work by Andrew = 41 days

And, the number of days to finish the same work by Scott = 46 days

Thus, the number of days to finish the work by Andrew and Scott together = ?

Here,

∵ In 41 days the work done by Andrew = 1

∴ In 1 day, the work done by Andrew = 1/41 part

Similarly,

∵ In 46 days the work done by Scott = 1

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

Now, in 1 day, the work done by Andrew and Scott together

= In 1 day work done by Andrew + In 1 day the work done by Scott

= 1/41 + 1/46

= 46 + 41/1886

= 87/1886 part of work

This means in 1 day, 87/1886 part of work is done by Andrew and Scott working together.

Now, the number of days required to finish 87/1886 part of work by Andrew + Scott working together = 1

∴ the number of days required to finish 1 work by Andrew + Scott together

= 1/87/1886

= 1 × 1886/87 = 1886/87 days

= 21 59/87 days = or 21.678 days

Thus, Andrew and Scott working together will finish the work in 21 59/87 days = or 21.678 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 Andrew = 41 days

And the number of days required to finish the same work by Scott = 46 days

Thus, the number of days required to finish the work Andrew and Scott working together = ?

Here a = 41 days

And, b = 46 days

Thus, using formula a × b/a + b days

The number of days required to finish the work when Andrew and Scott working together

= 41 × 46/41 + 46 days

= 1886/87 days

= 21 59/87 days or 21.678

Thus, Andrew and Scott together will finish the work in 21 59/87 days or 21.678 days Answer


Similar Questions

(1) Thomas can finish a work in 17 days. Charles can finish the same work in 18 days while Christopher can finish the work in 19 days. How long will it take to finish it if they work together?

(2) Matthew can finish a work in 29 days. Mark can finish the same work in 34 days while Donald can finish the work in 39 days. How long will it take to finish it if they work together?

(3) 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?

(4) Andrew can finish a work in 37 days. Joshua can finish the same work in 38 days while Kenneth can finish the work in 39 days. How long will it take to finish it if they work together?

(5) Jack can finish a work in 99 days. Jerry can finish the same work in 104 days while Tyler can finish the work in 109 days. How long will it take to finish it if they work together?

(6) If Andrew can finish the work in 38 days and Scott can finish the same work in 42 days, then in how many days both can finish the work together?

(7) 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?

(8) Paul can finish a work in 39 days. Joshua can finish the same work in 44 days while Kenneth can finish the work in 49 days. How long will it take to finish it if they work together?

(9) If Donna can finish the work in 42 days and Brandon can finish the same work in 47 days, then in how many days both can finish the work together?

(10) If Frank can finish the work in 93 days and Randy can finish the same work in 98 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. ©