
Explanation:
Since we have given that
The prices of three t-shirts styles i.e $24, $30, $36 with their probability is given by

As we know that,


Now,

and

So,

So, the expected value of a t-shirt = $31.
The answer is B, because it all goes in order so no need for parentheses
(93+67+78+44+123)/5=405/5=81 pizzas per day on average
C is your answer.
2(x+5) =20 is the translation
X can be 4 or -4
As a minus by a minus is a positive