Since they are independent events to find the probability of both is P(A) * P(B)
P(A) = P(Heads) =

P(B) = P(Roll ≥ 4) =

Now multiply those fractions together

= P(Heads & ≥ 4)
Yes, he is correct, using the distributive property you get the same answer
12 oz = 1.15
24 oz = 2.79
Let's see if 2x12oz is equal, less, or more than the 24oz.
1.15 x 2 = 2.30
2.30<2.79
The 12 oz is a better buy.