Please help me I’m very confused

Trish receives $450 on the first of each month. josh receives $450 on the last day of each month. both trish and josh will receive payments for next four years. at a discount rate of 9.5 percent, what is the difference in the present value of these two sets of payments?

Agroup of randomly selected apple valley high school students were asked to pick their favorite gym class. the table below shows the results of the survey. there are 528 students at apple valley high school. gym class number of students racquet sports 1 team sports 9 track and field 17 bowling 13 based on the data, what is the most reasonable estimate for the number of students at apple valley high school whose favorite gym class is bowling? choose 1 answer a. 9 b. 13 c. 119 d. 172

Answer asap ill give ! ’ a sample of radioactive material decays over time. the number of grams, y , of the material remaining x days after the sample is discovered is given by the equation y = 10(0.5)^x. what does the number 10 represents in the equation? a. the half-life of the radioactive material, in days b. the amount of the sample, in grams, that decays each day c. the time, in days, it will take for the samples to decay completely d. the size of the sample, in grams, at the time the material was discovered