Question

X=8 y=20 find y when x=42

Answer 1

y= 105

Step-by-step explanation

X=8

Y=20

So,

x/y = 8/20

= 2/5

x=(2/5)y

y= (5/2)x

When x=42

y=(5/2)×42

=105

Answer 2

In this problem, we need to use the concept of proportions. Proportion says that two ratios (or fractions) are equal. So, we have two numbers, namely:

`x=8 \ and \ y=20`

So, the given proportion is:

`(x)/(y)=(8)/(20) \\ \\ \therefore (x)/(y)=(2)/(5)`

That is, x-out-of-y is equal to 2-out-of-5

On the other hand, we know that
`x=42`, so by using the previous proportion we have:

`(42)/(y)=(2)/(5) \\ \\ Isolating \ y: \\ \\ y=(42 * 5)/(2) \\ \\ y=\boxed{105}`