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

(1) If Kevin can finish the work in 44 days and Frank can finish the same work in 48 days, then in how many days both can finish the work together?

(2) If Robert can finish a work in 4 days and Bob can finish the same work in 6 days, then in how many days they both can finish the work working together?

(3) If Charles can finish the work in 20 days and Kenneth can finish the same work in 24 days, then in how many days both can finish the work together?

(4) John can finish a work in 5 days. Michael can finish the same work in 6 days while David can finish the work in 7 days. How long will it take to finish it if they work together?

(5) Karen can finish a work in 20 days. Lisa can finish the same work in 21 days while Nancy can finish the work in 22 days. How long will it take to finish it if they work together?

(6) 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?

(7) 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?

(8) If Margaret can finish the work in 32 days and Ryan can finish the same work in 37 days, then in how many days both can finish the work together?

(9) Eric can finish a work in 71 days. Stephen can finish the same work in 76 days while Larry can finish the work in 81 days. How long will it take to finish it if they work together?

(10) Angela can finish a work in 70 days. Anna can finish the same work in 75 days while Brenda can finish the work in 80 days. How long will it take to finish it if they work together?


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