Time and Work
MCQs Math


Question:     If Samantha can finish the work in 86 days and Logan can finish the same work in 91 days, then in how many days both can finish the work together?


Correct Answer  44 38/177 days or 44.215 days

Solution And Explanation

Solution

Given,

The number of days to finish the work by Samantha = 86 days

And, the number of days to finish the same work by Logan = 91 days

Thus, the number of days to finish the work by Samantha and Logan together = ?

Here,

∵ In 86 days the work done by Samantha = 1

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

Similarly,

∵ In 91 days the work done by Logan = 1

∴ In 1 day, the work done by Logan = 1/91 part

Now, in 1 day, the work done by Samantha and Logan together

= In 1 day work done by Samantha + In 1 day the work done by Logan

= 1/86 + 1/91

= 91 + 86/7826

= 177/7826 part of work

This means in 1 day, 177/7826 part of work is done by Samantha and Logan working together.

Now, the number of days required to finish 177/7826 part of work by Samantha + Logan working together = 1

∴ the number of days required to finish 1 work by Samantha + Logan together

= 1/177/7826

= 1 × 7826/177 = 7826/177 days

= 44 38/177 days = or 44.215 days

Thus, Samantha and Logan working together will finish the work in 44 38/177 days = or 44.215 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 Samantha = 86 days

And the number of days required to finish the same work by Logan = 91 days

Thus, the number of days required to finish the work Samantha and Logan working together = ?

Here a = 86 days

And, b = 91 days

Thus, using formula a × b/a + b days

The number of days required to finish the work when Samantha and Logan working together

= 86 × 91/86 + 91 days

= 7826/177 days

= 44 38/177 days or 44.215

Thus, Samantha and Logan together will finish the work in 44 38/177 days or 44.215 days Answer


Similar Questions

(1) If John can finish the work in 6 days and Richard can finish the same work in 10 days, then in how many days both can finish the work together?

(2) If Rebecca can finish the work in 58 days and Henry can finish the same work in 63 days, then in how many days both can finish the work together?

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(7) If Nicole can finish the work in 82 days and Billy can finish the same work in 87 days, then in how many days both can finish the work together?

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