How do I solve this AP Chemistry rate law problem?

Question

The rate expression for a particular reaction is Rate=[A][B]^2. If the initial concentration of B is increased from 0.1M to 0.3M, the initial rate will increase by what factor?

Answer 1

Since it is 2nd order with respect to B, tripling the [B] from 0.1 to 0.3 M will increase the rate by 3² = 9 times, or a factor of 9.