Question

If y varies directly as x, and y is 6 when x is 72, what is the value of y when x is 8?

1/9
2/3
54
96

Answer 1

2/3

Explanation:

Y varies directly as x

Y =kx

Y=6 when x = 72

First find the relationship between y and x.

i.e find the value of k

Substitute the value of x and y

6 = k *72

Make k the subject of the formula

K = 6/72

K= 1/12

:. The rlationship between x and y is

Y = 1/12x

When x is 8

Y = 1/12 * 8

Y = 8/12

Y = 2/3 and that is the answer

Hope it helped you

Answer 2

The answer is : 2/3

Explanation:

Given is that y varies directly as x.

Means as y increases or decreases, x also increases or decreases.

When y is 6 when x is 72,

So, when x = 8, we have to find y.

We can write the relation as follows:

`(6)/(y)= (72)/(8)`

`72y=48`

`y=(48)/(72)` =
`(2)/(3)`