If p and q vary inversely, then you can write:
p = k/q
where k is a constant. If q is 10 when p is 7, you can calculate the value of k, as follow:
7 = k/10 multiply by 10 both sides
10·7 = k
70 = k
then, the rekation in betqeen p and q is:
p = 70/q
when p is 35, you have:
35 = 70/q multiply by q both sides
35·q = 70 divide by 35 both sides
q = 70/35
q = 2
Hence, q is 2 when p is 35