Answer:
3.5 is the correct answer
The answer would be 16 S'mores and the limiting reactant would be the grahams.
(This is assuming that S'mores would need 2 grahams, 1 marshmallow and 1 chocolate piece.)
Limiting reactant would be the reactant that runs out first.
Let's take your problem into account and see what we have:
48 marshallows
32 grahams (2 x 16 per pack)
45 chocolate pieces (5 x 15 pieces per bar)
Since need 2 of the grahams per S'more then the maximum yield of the grahams is 16 S'mores.
The maximum yield of marshmallows is 48.
The maximum yield of chocolate is 45.
Since you cannot make S'mores without the grahams, then you can only make 16 S'mores before the grahams run out.
We are looking to find P(X>60 students)
X is normally distributed with mean 50 and standard deviation 5
We need to find the z-score of 60 students

To find the probability of P(Z>2), we can do 1 - P(Z<2)
So we read the probability when Z<2 which is 0.9772, then subtract from one we get 0.0228
The number of students that has score more than 60 is 0.0228 x 1000 = 228 students
12 days. 60 is a quarter of 240. So, multiply 60 by 4 to get 240.