Question

Jamal works as an electrician's apprentice. He rewired 4 electrical outlets in 1 and one-halfhours. If he works at the same pace for 7.5 hours, how many outlets will he rewire? 5 outlets 13 outlets 20 outlets 30 outlets

Answer 1

20 outlets

Explanation:

Number of outlets rewired in 1.5 hours = 4

Jamal keeps on working at the same pace 7.5 hours.

To find:

Number of outlets rewired = ?

Solution:

The answer can be found by using the unitary method.

First of all, we need to find number of outlets rewired in 1 hour.

And then, we can multiply with 7.5 to find out the answer.

Number of outlets rewired in 1.5 hours = 4

Number of outlets rewired in 1 hour =
`(4)/(1.5) = (40)/(15) = (8)/(3)`

Number of outlets rewired in 7.5 hours =
`(8)/(3)* 7.5 = \bold{20}`

So, 20 outlets can be rewired in 7.5 hours.

Answer 2

Given :

Jamal works as an electrician's apprentice. He rewired 4 electrical outlets in 1 and one-halfhours.

To Find :

If he works at the same pace for 7.5 hours, how many outlets will he rewire.

Solution :

Let, rate of wire rewired in one hour is r.

So,
`r=(4)/(1.5)\ = (8)/(3)\ rewire/hour`.

Now, number of outlets rewired in 7.5 hours are :

`N=7.5*(8)/(3)\\\\N = 20`

Therefore, he will rewire 20 outlets in 7.5 hours.

Hence, this is the required solution.