Question

If Y is directly proportional to X then:
(k is a constant)

• A. $Y=kX$
• B. $Y=\frac{k}{X}$
• C. $Y=k+X$
• D. $Y=k-X$

Answer 1

The correct option is A $Y=kX$

If the two quantities are directly proportional, the increase of one quantity will increase the other quantity and vice versa.

When Y and X are in direct proportion
$\frac{Y}{X}=k$
or
$Y=kX$ where, k is constant.