Time and Work
MCQs Math


Question:     If Michael can finish the work in 8 days and Thomas can finish the same work in 11 days, then in how many days both can finish the work together?


Correct Answer  4 12/19 days or 4.632 days

Solution And Explanation

Solution

Given,

The number of days to finish the work by Michael = 8 days

And, the number of days to finish the same work by Thomas = 11 days

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

Here,

∵ In 8 days the work done by Michael = 1

∴ In 1 day, the work done by Michael = 1/8 part

Similarly,

∵ In 11 days the work done by Thomas = 1

∴ In 1 day, the work done by Thomas = 1/11 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

= 1/8 + 1/11

= 11 + 8/88

= 19/88 part of work

This means in 1 day, 19/88 part of work is done by Michael and Thomas working together.

Now, the number of days required to finish 19/88 part of work by Michael + Thomas working together = 1

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

= 1/19/88

= 1 × 88/19 = 88/19 days

= 4 12/19 days = or 4.632 days

Thus, Michael and Thomas working together will finish the work in 4 12/19 days = or 4.632 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 = 8 days

And the number of days required to finish the same work by Thomas = 11 days

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

Here a = 8 days

And, b = 11 days

Thus, using formula a × b/a + b days

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

= 8 × 11/8 + 11 days

= 88/19 days

= 4 12/19 days or 4.632

Thus, Michael and Thomas together will finish the work in 4 12/19 days or 4.632 days Answer


Similar Questions

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