Time and Work
MCQs Math


Question:     If Gary can finish the work in 67 days and Christian can finish the same work in 72 days, then in how many days both can finish the work together?


Correct Answer  34 98/139 days or 34.705 days

Solution And Explanation

Solution

Given,

The number of days to finish the work by Gary = 67 days

And, the number of days to finish the same work by Christian = 72 days

Thus, the number of days to finish the work by Gary and Christian together = ?

Here,

∵ In 67 days the work done by Gary = 1

∴ In 1 day, the work done by Gary = 1/67 part

Similarly,

∵ In 72 days the work done by Christian = 1

∴ In 1 day, the work done by Christian = 1/72 part

Now, in 1 day, the work done by Gary and Christian together

= In 1 day work done by Gary + In 1 day the work done by Christian

= 1/67 + 1/72

= 72 + 67/4824

= 139/4824 part of work

This means in 1 day, 139/4824 part of work is done by Gary and Christian working together.

Now, the number of days required to finish 139/4824 part of work by Gary + Christian working together = 1

∴ the number of days required to finish 1 work by Gary + Christian together

= 1/139/4824

= 1 × 4824/139 = 4824/139 days

= 34 98/139 days = or 34.705 days

Thus, Gary and Christian working together will finish the work in 34 98/139 days = or 34.705 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 Gary = 67 days

And the number of days required to finish the same work by Christian = 72 days

Thus, the number of days required to finish the work Gary and Christian working together = ?

Here a = 67 days

And, b = 72 days

Thus, using formula a × b/a + b days

The number of days required to finish the work when Gary and Christian working together

= 67 × 72/67 + 72 days

= 4824/139 days

= 34 98/139 days or 34.705

Thus, Gary and Christian together will finish the work in 34 98/139 days or 34.705 days Answer


Similar Questions

(1) If Frank can finish the work in 93 days and Randy can finish the same work in 98 days, then in how many days both can finish the work together?

(2) If Thomas can finish the work in 21 days and Andrew can finish the same work in 26 days, then in how many days both can finish the work together?

(3) Ronald can finish a work in 55 days. Jason can finish the same work in 60 days while Jeffrey can finish the work in 65 days. How long will it take to finish it if they work together?

(4) If Kenneth can finish the work in 42 days and Gregory can finish the same work in 45 days, then in how many days both can finish the work together?

(5) 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?

(6) Ryan can finish a work in 63 days. Gary can finish the same work in 68 days while Nicholas can finish the work in 73 days. How long will it take to finish it if they work together?

(7) If William can finish the work in 34 days and Matthew can finish the same work in 50 days, then in how many days both can finish the work together?

(8) If Karen can finish the work in 21 days and Kevin can finish the same work in 25 days, then in how many days both can finish the work together?

(9) If Lisa can finish the work in 23 days and George can finish the same work in 26 days, then in how many days both can finish the work together?

(10) If Karen can finish the work in 24 days and Kevin can finish the same work in 29 days, then in how many days both can finish the work together?


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