Time and Work
MCQs Math


Question:     If Donald can finish the work in 32 days and Nicholas can finish the same work in 35 days, then in how many days both can finish the work together?


Correct Answer  16 48/67 days or 16.716 days

Solution And Explanation

Solution

Given,

The number of days to finish the work by Donald = 32 days

And, the number of days to finish the same work by Nicholas = 35 days

Thus, the number of days to finish the work by Donald and Nicholas together = ?

Here,

∵ In 32 days the work done by Donald = 1

∴ In 1 day, the work done by Donald = 1/32 part

Similarly,

∵ In 35 days the work done by Nicholas = 1

∴ In 1 day, the work done by Nicholas = 1/35 part

Now, in 1 day, the work done by Donald and Nicholas together

= In 1 day work done by Donald + In 1 day the work done by Nicholas

= 1/32 + 1/35

= 35 + 32/1120

= 67/1120 part of work

This means in 1 day, 67/1120 part of work is done by Donald and Nicholas working together.

Now, the number of days required to finish 67/1120 part of work by Donald + Nicholas working together = 1

∴ the number of days required to finish 1 work by Donald + Nicholas together

= 1/67/1120

= 1 × 1120/67 = 1120/67 days

= 16 48/67 days = or 16.716 days

Thus, Donald and Nicholas working together will finish the work in 16 48/67 days = or 16.716 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 Donald = 32 days

And the number of days required to finish the same work by Nicholas = 35 days

Thus, the number of days required to finish the work Donald and Nicholas working together = ?

Here a = 32 days

And, b = 35 days

Thus, using formula a × b/a + b days

The number of days required to finish the work when Donald and Nicholas working together

= 32 × 35/32 + 35 days

= 1120/67 days

= 16 48/67 days or 16.716

Thus, Donald and Nicholas together will finish the work in 16 48/67 days or 16.716 days Answer


Similar Questions

(1) Benjamin can finish a work in 85 days. Gregory can finish the same work in 90 days while Alexander can finish the work in 95 days. How long will it take to finish it if they work together?

(2) 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?

(3) Raymond can finish a work in 97 days. Dennis can finish the same work in 102 days while Jerry can finish the work in 107 days. How long will it take to finish it if they work together?

(4) Jonathan can finish a work in 73 days. Larry can finish the same work in 78 days while Justin can finish the work in 83 days. How long will it take to finish it if they work together?

(5) Patricia can finish a work in 4 days. Jennifer can finish the same work in 5 days while Linda can finish the work in 6 days. How long will it take to finish it if they work together?

(6) 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?

(7) 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?

(8) Jacob can finish a work in 65 days. Nicholas can finish the same work in 70 days while Eric can finish the work in 75 days. How long will it take to finish it if they work together?

(9) 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?

(10) If Kevin can finish the work in 44 days and Frank can finish the same work in 48 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. ©