Answer
$3.77×10^{−16}$
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_2*(1/4)^{30}=\boxed{3.77×10^{−16}
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