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

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(2) If Amanda can finish the work in 45 days and Patrick can finish the same work in 49 days, then in how many days both can finish the work together?

(3) Christopher can finish a work in 21 days. Daniel can finish the same work in 22 days while Matthew can finish the work in 23 days. How long will it take to finish it if they work together?

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(6) If Dorothy can finish the work in 47 days and Jack can finish the same work in 50 days, then in how many days both can finish the work together?

(7) Nicholas can finish a work in 69 days. Jonathan can finish the same work in 74 days while Stephen can finish the work in 79 days. How long will it take to finish it if they work together?

(8) If Patricia can finish the work in 8 days and William can finish the same work in 13 days, then in how many days both can finish the work together?

(9) If Anthony can finish the work in 28 days and Jeffrey can finish the same work in 32 days, then in how many days both can finish the work together?

(10) If Jeffrey can finish the work in 61 days and Peter can finish the same work in 66 days, then in how many days both can finish the work together?


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