Question

If y is directly proportional with x and y = 36 when x = 30, what is the value of y when x = 40?

Answer 1

Answer:

y = 48

Step-by-step explanation:

given y is directly proportional to x then the equation connecting them is

y = kx ← k is the constant of proportionality

To find k use the condition y = 36 when x = 30

k = $\frac{y}{x}$ = $\frac{36}{30}$ = $\frac{6}{5}$

y = $\frac{6}{5}$ x ← equation of proportionality

When x = 40 then

y = $\frac{6}{5}$ × 40 = 48