Question:
In which of the following case, do the quantities vary directly with each other?
Solution:
Option (a)
Explanation: In option (a), the values of x is directly proportional to values of y, such as;
y = 4x
If we put the values of x = 0.5, 2, 8 and 32, we get the values of y as 2, 8, 32 and 128 respectively.