I think c I might be wrong tho :)
Answer:

Step-by-step explanation:
Height doubles at every 30 seconds, so let's call n how many times it happens, and the t the total time:
n = t/30
If the height doubles one time, it is multiplied by 2, if it doubles 2 times, it's multiplied by 2², for n times, it is multiplied by 2ⁿ, so for an initial height equal to 3:

Answer:
he will have to go one more week and all together it would be five weeks
Step-by-step explanation:
16/4=4
you need four more to get to 20, and if he does 4 quizzes a week he only needs one more week.
Answer:
94.7%
Step-by-step explanation:
If it is only winning or losing cards, then you can subtract 5.3 from 100 because probability is out of 100%
100-5.3 = 94.7
(a) need to find the number of books, we'll call it "b". then the money (6w) minus the cost of books (17b) equals change left over (w)
6w - 17b = w
6w - w = 17b
5w = 17b
(5/17)w = b
(b) if w = 34
(5/17) *34 = b
10 = b