Question

Y is inversely proportional to X.

When X=3, Y=8.

Work out the value of Y when X=8

Answer 1

`y \: = k \: (1)/(x) \: \\ where \: k \: is \: some \: constant`

for x = 3 y = 8

lets put it in equation

8 = k × (1/3)

k = 8×3=24

so now for x = 8

y = k/x = 24/ 8 = 3

Answer 2

y = 3

Explanation:

given y is inversely proportional to x then the equation relating them is

y =
`(k)/(x)` ← k is the constant of variation

To find k use the condition y = 8 when x = 3

k = yx = 8 × 3 = 24

y =
`(24)/(x)` ← equation of variation

When x = 8, then

y =
`(24)/(8)` = 3