Time and Work
MCQs Math


Question:     If Betty can finish the work in 27 days and Jason can finish the same work in 30 days, then in how many days both can finish the work together?


Correct Answer  14 4/19 days or 14.211 days

Solution And Explanation

Solution

Given,

The number of days to finish the work by Betty = 27 days

And, the number of days to finish the same work by Jason = 30 days

Thus, the number of days to finish the work by Betty and Jason together = ?

Here,

∵ In 27 days the work done by Betty = 1

∴ In 1 day, the work done by Betty = 1/27 part

Similarly,

∵ In 30 days the work done by Jason = 1

∴ In 1 day, the work done by Jason = 1/30 part

Now, in 1 day, the work done by Betty and Jason together

= In 1 day work done by Betty + In 1 day the work done by Jason

= 1/27 + 1/30

= 10 + 9/270

= 19/270 part of work

This means in 1 day, 19/270 part of work is done by Betty and Jason working together.

Now, the number of days required to finish 19/270 part of work by Betty + Jason working together = 1

∴ the number of days required to finish 1 work by Betty + Jason together

= 1/19/270

= 1 × 270/19 = 270/19 days

= 14 4/19 days = or 14.211 days

Thus, Betty and Jason working together will finish the work in 14 4/19 days = or 14.211 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 Betty = 27 days

And the number of days required to finish the same work by Jason = 30 days

Thus, the number of days required to finish the work Betty and Jason working together = ?

Here a = 27 days

And, b = 30 days

Thus, using formula a × b/a + b days

The number of days required to finish the work when Betty and Jason working together

= 27 × 30/27 + 30 days

= 810/57 days

= 810 ÷ 3/57 ÷ 3 = 270/19 days

= 14 4/19 days or 14.211

Thus, Betty and Jason together will finish the work in 14 4/19 days or 14.211 days Answer


Similar Questions

(1) Barbara can finish a work in 16 days. Jessica can finish the same work in 21 days while Sarah can finish the work in 26 days. How long will it take to finish it if they work together?

(2) Lisa can finish a work in 22 days. Nancy can finish the same work in 23 days while Betty can finish the work in 24 days. How long will it take to finish it if they work together?

(3) If Elizabeth can finish the work in 11 days and Daniel can finish the same work in 14 days, then in how many days both can finish the work together?

(4) If Barbara can finish the work in 13 days and Anthony can finish the same work in 17 days, then in how many days both can finish the work together?

(5) Joseph can finish a work in 19 days. Charles can finish the same work in 24 days while Christopher can finish the work in 29 days. How long will it take to finish it if they work together?

(6) If Stephen can finish the work in 75 days and Carl can finish the same work in 80 days, then in how many days both can finish the work together?

(7) David can finish a work in 9 days. William can finish the same work in 10 days while Richard can finish the work in 11 days. How long will it take to finish it if they work together?

(8) Brian can finish a work in 49 days. Timothy can finish the same work in 54 days while Ronald can finish the work in 59 days. How long will it take to finish it if they work together?

(9) Emily can finish a work in 36 days. Donna can finish the same work in 37 days while Michelle can finish the work in 38 days. How long will it take to finish it if they work together?

(10) If Ryan can finish the work in 63 days and Ethan can finish the same work in 68 days, then in how many days both can finish the work together?


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