8.9442719i<span> this is the answer</span>
Answer:
Let the no. Of cheese pizzas be x
Let the no. Of pepperoni pizzas be y
x + y = 45 (No. Of pizzas)
x = 45 - y
6x + 8.5y = 365 (cost of pizzas)
6(45-y) + 8.5y = 365
270 - 6y + 8.5y = 365
2.5y = 365 - 270
2.5y = 95
y = 95/2.5
y = 38
x = 7
Therefore 7 cheese pizzas were sold and 38 pepperoni pizzas were sold
Hope this helps!
Answer
a) y | p(y)
25 | 0.8
100 | 0.15
300 | 0.05
E(y) = ∑ y . p(y)
E(y) = 25 × 0.8 + 100 × 0.15 + 300 × 0.05
E(y) = 50
average class size equal to E(y) = 50
b) y | p(y)
25 | 
100 | 
300 | 
E(y) = ∑ y . p(y)
E(y) = 25 × 0.4 + 100 × 0.3 + 300 × 0.3
E(y) = 130
average class size equal to E(y) = 130
c) Average Student in the class in a school = 50
Average student at the school has student = 130