Time and Work
MCQs Math


Question:     If Joseph can finish the work in 16 days and Steven can finish the same work in 19 days, then in how many days both can finish the work together?


Correct Answer  8 24/35 days or 8.686 days

Solution And Explanation

Solution

Given,

The number of days to finish the work by Joseph = 16 days

And, the number of days to finish the same work by Steven = 19 days

Thus, the number of days to finish the work by Joseph and Steven together = ?

Here,

∵ In 16 days the work done by Joseph = 1

∴ In 1 day, the work done by Joseph = 1/16 part

Similarly,

∵ In 19 days the work done by Steven = 1

∴ In 1 day, the work done by Steven = 1/19 part

Now, in 1 day, the work done by Joseph and Steven together

= In 1 day work done by Joseph + In 1 day the work done by Steven

= 1/16 + 1/19

= 19 + 16/304

= 35/304 part of work

This means in 1 day, 35/304 part of work is done by Joseph and Steven working together.

Now, the number of days required to finish 35/304 part of work by Joseph + Steven working together = 1

∴ the number of days required to finish 1 work by Joseph + Steven together

= 1/35/304

= 1 × 304/35 = 304/35 days

= 8 24/35 days = or 8.686 days

Thus, Joseph and Steven working together will finish the work in 8 24/35 days = or 8.686 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 Joseph = 16 days

And the number of days required to finish the same work by Steven = 19 days

Thus, the number of days required to finish the work Joseph and Steven working together = ?

Here a = 16 days

And, b = 19 days

Thus, using formula a × b/a + b days

The number of days required to finish the work when Joseph and Steven working together

= 16 × 19/16 + 19 days

= 304/35 days

= 8 24/35 days or 8.686

Thus, Joseph and Steven together will finish the work in 8 24/35 days or 8.686 days Answer


Similar Questions

(1) Jessica can finish a work in 20 days. Karen can finish the same work in 25 days while Lisa can finish the work in 30 days. How long will it take to finish it if they work together?

(2) Carolyn can finish a work in 96 days. Catherine can finish the same work in 101 days while Maria can finish the work in 106 days. How long will it take to finish it if they work together?

(3) 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?

(4) Charles can finish a work in 19 days. Christopher can finish the same work in 20 days while Daniel can finish the work in 21 days. How long will it take to finish it if they work together?

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(6) If Brian can finish the work in 49 days and Raymond can finish the same work in 54 days, then in how many days both can finish the work together?

(7) If Gregory can finish the work in 89 days and Alan can finish the same work in 94 days, then in how many days both can finish the work together?

(8) Jessica can finish a work in 16 days. Sarah can finish the same work in 17 days while Karen can finish the work in 18 days. How long will it take to finish it if they work together?

(9) Steven can finish a work in 37 days. Andrew can finish the same work in 42 days while Joshua can finish the work in 47 days. How long will it take to finish it if they work together?

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