Time and Work
MCQs Math


Question:     Timothy can finish a work in 49 days. Ronald can finish the same work in 50 days while Edward can finish the work in 51 days. How long will it take to finish it if they work together?


Correct Answer  16 4966/7499 days or 16.662 days

Solution And Explanation

Solution

Given,

The number of days required to finish a piece of work by Timothy = 49 days

And, the number of days required to finish the same work by Ronald = 50 days

And, the number of days required to finish the same work by Edward = 51 days

Thus, the number of days required to finish the work by all of them if they work together = ?

Here,

∵ In 49 days the work is done by Timothy = 1

∴ The work done by Timothy in 1 day = 1/49

Similarly,

∵ In 50 days the work is done by Ronald = 1

∴ The work done by Ronald in 1 day = 1/50

Similarly,

∵ In 51 days the work is done by Edward = 1

∴ The work done by Edward in 1 day = 1/51 part

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

= Timothy's 1 day work + Ronald's 1 day work + Edward's 1 day work

= 1/49 + 1/50 + 1/51

= 2550 + 2499 + 2450/124950

= 7499/124950 part of work

This means in 1 day, 7499/124950 part of work is done by Timothy, Ronald and Edward working together.

Now, the number of days required to finish 7499/124950 part of work by Timothy, Ronald, and Edward working together = 1

∴ the number of days required to finish the whole work (1 work) by Timothy + Ronald + Edward together

= 1/7499/124950

= 1 × 124950/7499 = 124950/7499 days

= 16 4966/7499 days = or 16.662 days

Thus, Timothy, Ronald, and Edward working together will finish the total work (1 work) in 16 4966/7499 days = or 16.662 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, B can finish the same work in b days, and C can finish the work in c days
then working together the number of days required to finish the work
= a × b × c/ab + ac + bc days.

Here given,

The number of days required to finish the work by Timothy = 49 days

And the number of days required to finish the same work by Ronald = 50 days

And the number of days required to finish the work by Edward = 51 days

Thus, the number of days required to finish the work by Timothy, Ronald, and Edward together = ?

Here a = 49 days

And, b = 50 days

And, c = 51 days

Thus, using formula a × b × c/ab + ac + bc days

The number of days required to finish the work when Timothy, Ronald, and Edward working together

= 49 × 50 × 51/49 × 50 + 49 × 51 + 50 × 51 days

= 124950/2450 + 2499 + 2550 days

= 124950/7499 days

= 124950/7499 days

= 16 4966/7499 days or 16.662

Thus, Timothy, Ronald, and Edward together will finish the work in 16 4966/7499 days or 16.662 days Answer


Similar Questions

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