Time and Work
MCQs Math


Question:     If Michael can finish the work in 30 days and Thomas can finish the same work in 46 days, then in how many days both can finish the work together?


Correct Answer  18 3/19 days or 18.158 days

Solution And Explanation

Solution

Given,

The number of days to finish the work by Michael = 30 days

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

Thus, the number of days to finish the work by Michael and Thomas together = ?

Here,

∵ In 30 days the work done by Michael = 1

∴ In 1 day, the work done by Michael = 1/30 part

Similarly,

∵ In 46 days the work done by Thomas = 1

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

Now, in 1 day, the work done by Michael and Thomas together

= In 1 day work done by Michael + In 1 day the work done by Thomas

= 1/30 + 1/46

= 23 + 15/690

= 38/690 part of work

= 38 ÷ 2/690 ÷ 2 part of work

= 19/345 part of work

This means, in 1 day, 19/345 part of the work is done by Michael and Thomas together.

Now, the number of days required to finish 19/345 part of work by Michael + Thomas working together = 1

∴ the number of days required to finish 1 work by Michael + Thomas together

= 1/19/345

= 1 × 345/19 = 345/19 days

= 18 3/19 days = or 18.158 days

Thus, Michael and Thomas working together will finish the work in 18 3/19 days = or 18.158 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 Michael = 30 days

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

Thus, the number of days required to finish the work Michael and Thomas working together = ?

Here a = 30 days

And, b = 46 days

Thus, using formula a × b/a + b days

The number of days required to finish the work when Michael and Thomas working together

= 30 × 46/30 + 46 days

= 1380/76 days

= 1380 ÷ 4/76 ÷ 4 = 345/19 days

= 18 3/19 days or 18.158

Thus, Michael and Thomas together will finish the work in 18 3/19 days or 18.158 days Answer


Similar Questions

(1) If Thomas can finish the work in 18 days and Andrew can finish the same work in 22 days, then in how many days both can finish the work together?

(2) If Amy can finish the work in 68 days and Keith can finish the same work in 73 days, then in how many days both can finish the work together?

(3) If Patrick can finish the work in 95 days and Vincent can finish the same work in 100 days, then in how many days both can finish the work together?

(4) If Elizabeth can finish the work in 11 days and Daniel can finish the same work in 15 days, then in how many days both can finish the work together?

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(6) Christine can finish a work in 90 days. Rachel can finish the same work in 95 days while Carolyn can finish the work in 100 days. How long will it take to finish it if they work together?

(7) If Robert can finish a work in 4 days and Bob can finish the same work in 6 days, then in how many days they both can finish the work working together?

(8) If Jack can finish the work in 20 days and Bill can finish the same work in 30 days, then in how many days they both can finish the work working together?

(9) Jason can finish a work in 59 days. Ryan can finish the same work in 64 days while Jacob can finish the work in 69 days. How long will it take to finish it if they work together?

(10) Susan can finish a work in 14 days. Jessica can finish the same work in 15 days while Sarah can finish the work in 16 days. How long will it take to finish it if they work together?


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