Time and Work
MCQs Math


Question:     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?


Correct Answer  23 43/94 days or 23.457 days

Solution And Explanation

Solution

Given,

The number of days to finish the work by Amanda = 45 days

And, the number of days to finish the same work by Patrick = 49 days

Thus, the number of days to finish the work by Amanda and Patrick together = ?

Here,

∵ In 45 days the work done by Amanda = 1

∴ In 1 day, the work done by Amanda = 1/45 part

Similarly,

∵ In 49 days the work done by Patrick = 1

∴ In 1 day, the work done by Patrick = 1/49 part

Now, in 1 day, the work done by Amanda and Patrick together

= In 1 day work done by Amanda + In 1 day the work done by Patrick

= 1/45 + 1/49

= 49 + 45/2205

= 94/2205 part of work

This means in 1 day, 94/2205 part of work is done by Amanda and Patrick working together.

Now, the number of days required to finish 94/2205 part of work by Amanda + Patrick working together = 1

∴ the number of days required to finish 1 work by Amanda + Patrick together

= 1/94/2205

= 1 × 2205/94 = 2205/94 days

= 23 43/94 days = or 23.457 days

Thus, Amanda and Patrick working together will finish the work in 23 43/94 days = or 23.457 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 Amanda = 45 days

And the number of days required to finish the same work by Patrick = 49 days

Thus, the number of days required to finish the work Amanda and Patrick working together = ?

Here a = 45 days

And, b = 49 days

Thus, using formula a × b/a + b days

The number of days required to finish the work when Amanda and Patrick working together

= 45 × 49/45 + 49 days

= 2205/94 days

= 23 43/94 days or 23.457

Thus, Amanda and Patrick together will finish the work in 23 43/94 days or 23.457 days Answer


Similar Questions

(1) William can finish a work in 11 days. Richard can finish the same work in 12 days while Joseph can finish the work in 13 days. How long will it take to finish it if they work together?

(2) 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?

(3) If John can finish the work in 6 days and Richard can finish the same work in 9 days, then in how many days both can finish the work together?

(4) 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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(7) If Carol can finish the work in 46 days and Alexander can finish the same work in 51 days, then in how many days both can finish the work together?

(8) Sandra can finish a work in 34 days. Kimberly can finish the same work in 39 days while Emily can finish the work in 44 days. How long will it take to finish it if they work together?

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