Answer:
infinitely many
Step-by-step explanation:
You have the system
(1/2)x + 5y = 6
3x + 30y = 36
Multiplying the first equation by 6 results in 3x + 30y = 36, which is exactly the same as the second equation. The two graphs coincide, and so there are infinitely many solutions to this system
So, if Dylan has x dollars and he bought 3 tickets with them, the tickets were priced at k dollars per ticket. If he bought 5 tickets with the x dollars and saved 12 total dollars, it would be the same as buying the tickets with x-12 dollars, so we have:

So, with this we have:

If we're looking for a number that satisfies these constraints, we can work with modular arithmetic. We have:

So, we can use the chinese remainder theorem here. So, we clearly have x=3k, which means:

So, since we have x=3k, we also have x=3(5j+4)=15j+12.
So, clearly j=0 won't work so we should have j=1. That means our money per ticket for the five tickets is:

And our money per three tickets is:

This is easily verifiable. Three tickets needs 27 dollars and 5 tickets needs 15 dollars, which is 12 less than 27 dollars. So we have our money per three dollar ticket at 6 more than money per five dollar.
Answer:
D.
Step-by-step explanation:
Rate of change is another way of saying "find the gradient".
Sub any value into the gradient formula.
Possibilities of outcomes:
5, 5, 5
5, 5, 4
P(sum at least 14) = P(5,5,4) + P(5,5,5)
= 1/4 x 1/4 x 3/20 + 1/4 x 1/4 x 1/4
1/40
Assuming that the topping order is not important, you need to use the combination to solve this question. The number of toppings is 12 and then added 2, so the number will become: 12+2= 14 toppings
From 14 toppings, ian need to choose 3. The possible ways would be:
14C3= 14!/(14-3)!3!= 14*13*12/ 3*2= 364 possible ways