Eric, Riordan, David and Jenson participated in a Science quiz. The average number of points scored by Eric and Riordan was 78. The average number of points scored by Riordan and Jenson was 71.8. The average number of points scored by Eric, Riordan and Jenson was 72. The average number of points scored by David and Jenson was 68. How many points did each of them score?

1. Jenson
2. Eric
3. Riordan
4. David

(a)
Total score of Eric and Riordan
= 78 x 2
= 156

Total score of Riordan and Jenson
= 71.8 x 2
= 143.6

Total score of Eric, Riordan and Jenson
= 72 x 3
= 216

Jenson's score
= 216 - 156
= 60

(b)
Eric's score
= 216 - 143.6
= 72.4

(c)
Riordan's score
= 143.6 - 60
= 83.6

(d)
Total score of David and Jenson
= 68 x 2
= 136

David's score
= 136 - 60
= 76

Answer(s): (a) 60; (b) 72.4; (c) 83.6; (d) 76