Course Exam Mistake

In question 18 of the probability course exam, we can clearly see that there is a mistake in the correct answer explanation.

The correct answer is: (10 5) * (1/5)^5 * (4/5)^5 because it's necessary to use parentheses in order to raise both 1/5 and 4/5 to the power of 5.

I hope this makes sense.

Thanks