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) If A can do a piece of work in 2 days, B can do the same piece of work in 3 days, while C alone can do the same work in 4 days. Find the number of days to finish the work when they all will work together.

(2) Sarah can finish a work in 18 days. Karen can finish the same work in 19 days while Lisa can finish the work in 20 days. How long will it take to finish it if they work together?

(3) If Carol can finish the work in 43 days and Alexander can finish the same work in 46 days, then in how many days both can finish the work together?

(4) If Andrew can finish the work in 38 days and Scott can finish the same work in 42 days, then in how many days both can finish the work together?

(5) If Nancy can finish the work in 25 days and Ronald can finish the same work in 29 days, then in how many days both can finish the work together?

(6) 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?

(7) 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?

(8) If William can finish the work in 12 days and Matthew can finish the same work in 16 days, then in how many days both can finish the work together?

(9) If Andrew can finish the work in 41 days and Scott can finish the same work in 46 days, then in how many days both can finish the work together?

(10) Karen can finish a work in 24 days. Nancy can finish the same work in 29 days while Betty can finish the work in 34 days. How long will it take to finish it if they work together?


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