A. The water level in a reservoir increased 52 meters. If this was a 23% increase, what was the initial depth? B. The price of a jacket was reduced from $84 to $63. By what percentage was the price of the jacket reduced?

C. After a 25% discount, the price of a T-shirt was $12. What was the price before the discount?

I know the answers(don't now if there right) but i have to figure out how to do them please help.

The number of branches on a tree demonstrates the fibonacci sequence. how many branches would there be on the next two levels of this tree? 13 | | | m branches

Suppose that 3% of all athletes are using the endurance-enhancing hormone epo (you should be able to simply compute the percentage of all athletes that are not using epo). for our purposes, a “positive” test result is one that indicates presence of epo in an athlete’s bloodstream. the probability of a positive result, given the presence of epo is .99. the probability of a negative result, when epo is not present, is .90. what is the probability that a randomly selected athlete tests positive for epo? 0.0297

Find the power set of each of these sets, where a and b are distinct elements. a) {a} b) {a, b} c) {1, 2, 3, 4} show steps