Answer
$8.6736173799×10^{−19}
$
Work Step by Step
The chance of doing a specific problem correctly by guessing is $1/4$ Then, the number of ways to choose which ones are correct is dictated by $_{30}C_n$ where n is the number of correct OR incorrect (it doesn't matter because they will add up to 30 either way.
$$_{30}C_0*(1/4)^{30}=\boxed{8.6736173799×10^{−19}
}$$
