Time and Work
MCQs Math


Question:     If James can finish the work in 2 days and John can finish the same work in 6 days, then in how many days both can finish the work together?


Correct Answer  1 1/2 days or 1.5 days

Solution And Explanation

Solution

Given,

The number of days to finish the work by James = 2 days

And, the number of days to finish the same work by John = 6 days

Thus, the number of days to finish the work by James and John together = ?

Here,

∵ In 2 days the work done by James = 1

∴ In 1 day, the work done by James = 1/2 part

Similarly,

∵ In 6 days the work done by John = 1

∴ In 1 day, the work done by John = 1/6 part

Now, in 1 day, the work done by James and John together

= In 1 day work done by James + In 1 day the work done by John

= 1/2 + 1/6

= 3 + 1/6

= 4/6 part of work

= 4 ÷ 2/6 ÷ 2 part of work

= 2/3 part of work

This means, in 1 day, 2/3 part of the work is done by James and John together.

Now, the number of days required to finish 2/3 part of work by James + John working together = 1

∴ the number of days required to finish 1 work by James + John together

= 1/2/3

= 1 × 3/2 = 3/2 days

= 1 1/2 days = or 1.5 days

Thus, James and John working together will finish the work in 1 1/2 days = or 1.5 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 James = 2 days

And the number of days required to finish the same work by John = 6 days

Thus, the number of days required to finish the work James and John working together = ?

Here a = 2 days

And, b = 6 days

Thus, using formula a × b/a + b days

The number of days required to finish the work when James and John working together

= 2 × 6/2 + 6 days

= 12/8 days

= 12 ÷ 4/8 ÷ 4 = 3/2 days

= 1 1/2 days or 1.5

Thus, James and John together will finish the work in 1 1/2 days or 1.5 days Answer


Similar Questions

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(2) If Anna can finish the work in 74 days and Austin can finish the same work in 79 days, then in how many days both can finish the work together?

(3) If A can finish a work in 10 days and B can finish the same work in 15 days, then in how many days they both can finish the work working together?

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(6) Samuel can finish a work in 87 days. Alexander can finish the same work in 92 days while Frank can finish the work in 97 days. How long will it take to finish it if they work together?

(7) If Laura can finish the work in 62 days and Kyle can finish the same work in 67 days, then in how many days both can finish the work together?

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