Question

If a varies directly as b and a=3 when b=12, what is the value of a when b=18?

Answer 1

Answer:

a is proportional to b

a=kb

k is proportionality constant

k =a/b =3/12 =1/4

k=1/4 = a/b=a/18

1/4=a/18

a=18/4 =9/2 =4.5 answer