I Need Help With This One

At the beginning of 1974/75,2 years a man invested #2000 in a bank at 12.5% compound interest, if it degree #650 at the end of each two years to pay his son's school fees, after payment of interest to pay his son's school fees, how much did he have left at the beginning of the 1978/79 school year?

Abag contains 10 white golf balls and 6 striped golf balls. a golfer wants to add 112 golf balls to the bag. he wants the ratio of white to striped gold balls to remain the same. how many of each should he add?

How would you find the height of points on the circle? the topic is trigonometry.