Question

X is varying directly to Y. If x = 30 then Y = 7, and X = 15 then Y = ?

Answer 1

Answer:

It is given that x varies inversely as y i.e. x∝1y.

∴ x=ky, where k is constant of variation

⇒ x × y = k

When x = 15, y = 10.

∴ k = 15 × 10 = 150

So, the equation of variation is xy = 150.

When x = 20,

20y = 150

⇒ y = 15020 = 7.5