Time and Work
MCQs Math


Question:     If Sandra can finish the work in 31 days and Gary can finish the same work in 34 days, then in how many days both can finish the work together?


Correct Answer  16 14/65 days or 16.215 days

Solution And Explanation

Solution

Given,

The number of days to finish the work by Sandra = 31 days

And, the number of days to finish the same work by Gary = 34 days

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

Here,

∵ In 31 days the work done by Sandra = 1

∴ In 1 day, the work done by Sandra = 1/31 part

Similarly,

∵ In 34 days the work done by Gary = 1

∴ In 1 day, the work done by Gary = 1/34 part

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

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

= 1/31 + 1/34

= 34 + 31/1054

= 65/1054 part of work

This means in 1 day, 65/1054 part of work is done by Sandra and Gary working together.

Now, the number of days required to finish 65/1054 part of work by Sandra + Gary working together = 1

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

= 1/65/1054

= 1 × 1054/65 = 1054/65 days

= 16 14/65 days = or 16.215 days

Thus, Sandra and Gary working together will finish the work in 16 14/65 days = or 16.215 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 Sandra = 31 days

And the number of days required to finish the same work by Gary = 34 days

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

Here a = 31 days

And, b = 34 days

Thus, using formula a × b/a + b days

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

= 31 × 34/31 + 34 days

= 1054/65 days

= 16 14/65 days or 16.215

Thus, Sandra and Gary together will finish the work in 16 14/65 days or 16.215 days Answer


Similar Questions

(1) 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?

(2) If Daniel can finish the work in 24 days and Timothy can finish the same work in 28 days, then in how many days both can finish the work together?

(3) Thomas can finish a work in 21 days. Christopher can finish the same work in 26 days while Daniel can finish the work in 31 days. How long will it take to finish it if they 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) Brandon can finish a work in 83 days. Samuel can finish the same work in 88 days while Gregory can finish the work in 93 days. How long will it take to finish it if they work together?

(6) If Betty can finish the work in 30 days and Jason can finish the same work in 35 days, then in how many days both can finish the work together?

(7) Frank can finish a work in 93 days. Raymond can finish the same work in 98 days while Jack can finish the work in 103 days. How long will it take to finish it if they work together?

(8) Brian can finish a work in 49 days. Timothy can finish the same work in 54 days while Ronald can finish the work in 59 days. How long will it take to finish it if they work together?

(9) If Mark can finish the work in 30 days and Jacob can finish the same work in 33 days, then in how many days both can finish the work together?

(10) Jennifer can finish a work in 10 days. Elizabeth can finish the same work in 15 days while Barbara can finish the work in 20 days. How long will it take to finish it if they work together?


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