Riordan, Carl, Pierre and Ryan participated in a Chinese quiz. The average number of points scored by Riordan and Carl was 77. The average number of points scored by Carl and Ryan was 70.9. The average number of points scored by Riordan, Carl and Ryan was 72. The average number of points scored by Pierre and Ryan was 69. How many points did each of them score?

1. Ryan
2. Riordan
3. Carl
4. Pierre

(a)
Total score of Riordan and Carl
= 77 x 2
= 154

Total score of Carl and Ryan
= 70.9 x 2
= 141.8

Total score of Riordan, Carl and Ryan
= 72 x 3
= 216

Ryan's score
= 216 - 154
= 62

(b)
Riordan's score
= 216 - 141.8
= 74.2

(c)
Carl's score
= 141.8 - 62
= 79.8

(d)
Total score of Pierre and Ryan
= 69 x 2
= 138

Pierre's score
= 138 - 62
= 76

Answer(s): (a) 62; (b) 74.2; (c) 79.8; (d) 76