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?

Answer 1

The correct answer is: y = $\frac{2}{3}$

Explanation:

The direct relation can be written as follows:

$y \propto x$

Now to remove the proportional sign, we use the constant of proportionality, let's say k, as follows:

$y = kx$

When y = 6, x = 72, k will be:

$k =\frac{y}{x} \\ k =\frac{6}{72} = \frac{1}{12}$

Now we know the value of k, let's find the value of y when x = 8:

$y = kx \\ y =\frac{1}{12} * 8 =\frac{2}{3}$

Hence the correct answer is: y = $\frac{2}{3}$

Answer 2

X÷y=72÷6=12    8÷12=2/3 y would equal 2/3