Assuming that he made x assists, then the number of goals were x+50,
Had he scored 15 more goals and 15 more points he would have attained 1200 points.
Therefore, assists will be x+15 and the goals will be x + 65,
Hence, (x+ 15) + (x+65) = 1200
= 2x + 80 =1200
2x = 1120
x = 560
Therefore, Derek had, 560 assists, 610 goals and a total of 1170 points