Time and Work
MCQs Math


Question:     If Cynthia can finish the work in 64 days and Walter can finish the same work in 69 days, then in how many days both can finish the work together?


Correct Answer  33 27/133 days or 33.203 days

Solution And Explanation

Solution

Given,

The number of days to finish the work by Cynthia = 64 days

And, the number of days to finish the same work by Walter = 69 days

Thus, the number of days to finish the work by Cynthia and Walter together = ?

Here,

∵ In 64 days the work done by Cynthia = 1

∴ In 1 day, the work done by Cynthia = 1/64 part

Similarly,

∵ In 69 days the work done by Walter = 1

∴ In 1 day, the work done by Walter = 1/69 part

Now, in 1 day, the work done by Cynthia and Walter together

= In 1 day work done by Cynthia + In 1 day the work done by Walter

= 1/64 + 1/69

= 69 + 64/4416

= 133/4416 part of work

This means in 1 day, 133/4416 part of work is done by Cynthia and Walter working together.

Now, the number of days required to finish 133/4416 part of work by Cynthia + Walter working together = 1

∴ the number of days required to finish 1 work by Cynthia + Walter together

= 1/133/4416

= 1 × 4416/133 = 4416/133 days

= 33 27/133 days = or 33.203 days

Thus, Cynthia and Walter working together will finish the work in 33 27/133 days = or 33.203 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 Cynthia = 64 days

And the number of days required to finish the same work by Walter = 69 days

Thus, the number of days required to finish the work Cynthia and Walter working together = ?

Here a = 64 days

And, b = 69 days

Thus, using formula a × b/a + b days

The number of days required to finish the work when Cynthia and Walter working together

= 64 × 69/64 + 69 days

= 4416/133 days

= 33 27/133 days or 33.203

Thus, Cynthia and Walter together will finish the work in 33 27/133 days or 33.203 days Answer


Similar Questions

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(2) If Charles can finish the work in 23 days and Kenneth can finish the same work in 28 days, then in how many days both can finish the work together?

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(6) If Patricia can finish the work in 27 days and William can finish the same work in 43 days, then in how many days both can finish the work together?

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