Question

If a and b vary directly and a = 6 when b = 4, what will be the value of a when b = 16?

Answer 1

"Vary directly" is another way of saying "directly proportional".

In simple English, this just means, as one increases, the other increases too.

a = 6

b = 4

The question says find out what a is when b is 16.

First, lets find how many times larger b has gotten.

16/4 = 4

b had gotten 4 times bigger to go from b=4 to b=16

If a is varying directly, it means that it will also get 4 times bigger.

Therefore, a = 6 x 4 = 24