Time and Work
MCQs Math


Question:     If Scott can finish the work in 81 days and Bryan can finish the same work in 86 days, then in how many days both can finish the work together?


Correct Answer  41 119/167 days or 41.713 days

Solution And Explanation

Solution

Given,

The number of days to finish the work by Scott = 81 days

And, the number of days to finish the same work by Bryan = 86 days

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

Here,

∵ In 81 days the work done by Scott = 1

∴ In 1 day, the work done by Scott = 1/81 part

Similarly,

∵ In 86 days the work done by Bryan = 1

∴ In 1 day, the work done by Bryan = 1/86 part

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

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

= 1/81 + 1/86

= 86 + 81/6966

= 167/6966 part of work

This means in 1 day, 167/6966 part of work is done by Scott and Bryan working together.

Now, the number of days required to finish 167/6966 part of work by Scott + Bryan working together = 1

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

= 1/167/6966

= 1 × 6966/167 = 6966/167 days

= 41 119/167 days = or 41.713 days

Thus, Scott and Bryan working together will finish the work in 41 119/167 days = or 41.713 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 Scott = 81 days

And the number of days required to finish the same work by Bryan = 86 days

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

Here a = 81 days

And, b = 86 days

Thus, using formula a × b/a + b days

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

= 81 × 86/81 + 86 days

= 6966/167 days

= 41 119/167 days or 41.713

Thus, Scott and Bryan together will finish the work in 41 119/167 days or 41.713 days Answer


Similar Questions

(1) If Matthew can finish the work in 26 days and Edward can finish the same work in 29 days, then in how many days both can finish the work together?

(2) If Carol can finish the work in 43 days and Alexander can finish the same work in 46 days, then in how many days both can finish the work together?

(3) Jessica can finish a work in 20 days. Karen can finish the same work in 25 days while Lisa can finish the work in 30 days. How long will it take to finish it if they work together?

(4) Justin can finish a work in 79 days. Brandon can finish the same work in 84 days while Benjamin can finish the work in 89 days. How long will it take to finish it if they work together?

(5) If Richard can finish the work in 14 days and Mark can finish the same work in 17 days, then in how many days both can finish the work together?

(6) If Andrew can finish the work in 38 days and Scott can finish the same work in 41 days, then in how many days both can finish the work together?

(7) Kenneth can finish a work in 41 days. Kevin can finish the same work in 42 days while Brian can finish the work in 43 days. How long will it take to finish it if they work together?

(8) 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?

(9) Kevin can finish a work in 47 days. George can finish the same work in 52 days while Timothy can finish the work in 57 days. How long will it take to finish it if they work together?

(10) If Charles can finish the work in 23 days and Kenneth can finish the same work in 28 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. ©