The correct answer is 8
Because
In triangle ORB
OR=(OB^2-RB^2)^1/2
OR=(17^2-15^2)^1/2
OR=(289-225)^1/2
OR=(64)^1/2
OR=8
RB=AB/2 so I kept its value 15 and ^1/2 refers to square root
50 students participated in the survey, if you need help with 2, 3, & 4, just comment and ask
The exact calculations:
Principal, P=3000
interest rate = 33% per year
Period, t=10 years
Future value



Interest
= future value - principal
= 81337.92-3000
=
78337.92 (to the nearest cent)