The answer would be the third one
You will choose 1 cheese 3 different ways because there are three types of cheeses.
You will choose your topings 6 different ways. 4!/(2!2!) = 4*3/2 = 6
Therefore you will be able to get 6 * 3 different pizzas = 18 pizza combinations.
To confirm the toppings, suppose they are (M)ushrooms (P)epperoni (O)nions and (B)acon
M P
M O
M B
P O
P B
O B
Total 6.The order doesn't matter here. M O is the same thing as OM
18 because they need to be identical and you only have 18 chocolate bars
Given is the function for number of adults who visit fair at day 'd' after its opening, a(d) = −0.3d² + 4d + 9.
Given is the function for number of children who visit fair at day 'd' after its opening, c(d) = −0.2d² + 5d + 11.
Any function f(d) to find excess of children more than adults can be written as follows :-
f(d) = c(d) - a(d).
⇒ f(d) = (−0.2d² + 5d + 11) - (−0.3d² + 4d + 9)
⇒ f(d) = -0.2d² + 0.3d² + 5d - 4d + 11 - 9
⇒ f(d) = 0.1d² + d + 2
2*(x-5) = -33, so x-5 = -16.5, so x = -11.5
This is assuming that "the difference between a and b" is a-b, which seems to be the accepted interpretation.
