Answer
The rate increases to eight times the original rate.
Step-by-step explanation
When the concentration of each reaction is doubled, the rate increases by eighth compared to the initial rate.
Example: Rate =k[A][B]^2
Lets assume : [A]1 = 0.1 and [A]2 = 0.2
[B]1 = 0.2 and [B]2 = 0.4
Initially: Rate = (0.1)(0.2)^2 = 4x10^-3
After doubling: Rate = (0.2)(0.4)^2 = 0.032
Divide the final answer by the initial one
=> 0.032/4x10^-3 = 8