Question

The amount of time it takes p people to paint d doors varies directly with the number of doors inversely with the number of people. Four people can paint 10 doors in 2 hours. How many people will it take to paint 25 doors in 5 hours?

A)4
B)5
C)10
D)20

Answer 1

It is (A.) 4

Explanation:

Answer 2

4 people

Explanation:

We are given that The amount of time it takes p people to paint d doors varies directly with the number of doors inversely with the number of people.

Let constant of propotionality be k

There are 4 people , 10 doors and 2 hours.

Since we are given that time varies directly with no. of doors and inversely with no. of people

`2= k * (10)/(4)`

`(2* 4)/(10)= k`

`(8)/(10)= k`

`(4)/(5)= k`

Now we are supposed to find that How many people will it take to paint 25 doors in 5 hours

⇒
`5= k * (25)/(d)`

⇒
`5=(4)/(5) * (25)/(d)`

⇒
`d=(4)/(5) *(25)/(5)`

⇒
`d=4`

Hence it will take 4 people to paint 25 doors in 5 hours.