Time and Work
MCQs Math


Question:     If Katherine can finish the work in 88 days and Willie can finish the same work in 93 days, then in how many days both can finish the work together?


Correct Answer  45 39/181 days or 45.215 days

Solution And Explanation

Solution

Given,

The number of days to finish the work by Katherine = 88 days

And, the number of days to finish the same work by Willie = 93 days

Thus, the number of days to finish the work by Katherine and Willie together = ?

Here,

∵ In 88 days the work done by Katherine = 1

∴ In 1 day, the work done by Katherine = 1/88 part

Similarly,

∵ In 93 days the work done by Willie = 1

∴ In 1 day, the work done by Willie = 1/93 part

Now, in 1 day, the work done by Katherine and Willie together

= In 1 day work done by Katherine + In 1 day the work done by Willie

= 1/88 + 1/93

= 93 + 88/8184

= 181/8184 part of work

This means in 1 day, 181/8184 part of work is done by Katherine and Willie working together.

Now, the number of days required to finish 181/8184 part of work by Katherine + Willie working together = 1

∴ the number of days required to finish 1 work by Katherine + Willie together

= 1/181/8184

= 1 × 8184/181 = 8184/181 days

= 45 39/181 days = or 45.215 days

Thus, Katherine and Willie working together will finish the work in 45 39/181 days = or 45.215 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 Katherine = 88 days

And the number of days required to finish the same work by Willie = 93 days

Thus, the number of days required to finish the work Katherine and Willie working together = ?

Here a = 88 days

And, b = 93 days

Thus, using formula a × b/a + b days

The number of days required to finish the work when Katherine and Willie working together

= 88 × 93/88 + 93 days

= 8184/181 days

= 45 39/181 days or 45.215

Thus, Katherine and Willie together will finish the work in 45 39/181 days or 45.215 days Answer


Similar Questions

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(2) Brian can finish a work in 45 days. George can finish the same work in 46 days while Timothy can finish the work in 47 days. How long will it take to finish it if they work together?

(3) If Sandra can finish the work in 31 days and Gary can finish the same work in 35 days, then in how many days both can finish the work together?

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(6) Jonathan can finish a work in 73 days. Larry can finish the same work in 78 days while Justin can finish the work in 83 days. How long will it take to finish it if they work together?

(7) If Robert can finish the work in 4 days and David can finish the same work in 7 days, then in how many days both can finish the work together?

(8) If Sarah can finish the work in 22 days and Joshua can finish the same work in 27 days, then in how many days both can finish the work together?

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