Time and Work
MCQs Math


Question:     If Ronald can finish the work in 55 days and Jose can finish the same work in 60 days, then in how many days both can finish the work together?


Correct Answer  28 16/23 days or 28.696 days

Solution And Explanation

Solution

Given,

The number of days to finish the work by Ronald = 55 days

And, the number of days to finish the same work by Jose = 60 days

Thus, the number of days to finish the work by Ronald and Jose together = ?

Here,

∵ In 55 days the work done by Ronald = 1

∴ In 1 day, the work done by Ronald = 1/55 part

Similarly,

∵ In 60 days the work done by Jose = 1

∴ In 1 day, the work done by Jose = 1/60 part

Now, in 1 day, the work done by Ronald and Jose together

= In 1 day work done by Ronald + In 1 day the work done by Jose

= 1/55 + 1/60

= 12 + 11/660

= 23/660 part of work

This means in 1 day, 23/660 part of work is done by Ronald and Jose working together.

Now, the number of days required to finish 23/660 part of work by Ronald + Jose working together = 1

∴ the number of days required to finish 1 work by Ronald + Jose together

= 1/23/660

= 1 × 660/23 = 660/23 days

= 28 16/23 days = or 28.696 days

Thus, Ronald and Jose working together will finish the work in 28 16/23 days = or 28.696 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 Ronald = 55 days

And the number of days required to finish the same work by Jose = 60 days

Thus, the number of days required to finish the work Ronald and Jose working together = ?

Here a = 55 days

And, b = 60 days

Thus, using formula a × b/a + b days

The number of days required to finish the work when Ronald and Jose working together

= 55 × 60/55 + 60 days

= 3300/115 days

= 3300 ÷ 5/115 ÷ 5 = 660/23 days

= 28 16/23 days or 28.696

Thus, Ronald and Jose together will finish the work in 28 16/23 days or 28.696 days Answer


Similar Questions

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(2) Laura can finish a work in 62 days. Kathleen can finish the same work in 67 days while Amy can finish the work in 72 days. How long will it take to finish it if they work together?

(3) 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?

(4) 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?

(5) If Elizabeth can finish the work in 11 days and Daniel can finish the same work in 15 days, then in how many days both can finish the work together?

(6) Stephanie can finish a work in 56 days. Sharon can finish the same work in 61 days while Laura can finish the work in 66 days. How long will it take to finish it if they work together?

(7) Gary can finish a work in 67 days. Eric can finish the same work in 72 days while Jonathan can finish the work in 77 days. How long will it take to finish it if they work together?

(8) If Amy can finish the work in 68 days and Keith can finish the same work in 73 days, then in how many days both can finish the work together?

(9) Joshua can finish a work in 39 days. Kenneth can finish the same work in 40 days while Kevin can finish the work in 41 days. How long will it take to finish it if they work together?

(10) If Dorothy can finish the work in 50 days and Jack can finish the same work in 55 days, then in how many days both can finish the work together?


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