Gabriel, Ahmad, Ken and David participated in a Science quiz. The average number of points scored by Gabriel and Ahmad was 75. The average number of points scored by Ahmad and David was 71.3. The average number of points scored by Gabriel, Ahmad and David was 71. The average number of points scored by Ken and David was 68. How many points did each of them score?

1. David
2. Gabriel
3. Ahmad
4. Ken

(a)
Total score of Gabriel and Ahmad
= 75 x 2
= 150

Total score of Ahmad and David
= 71.3 x 2
= 142.6

Total score of Gabriel, Ahmad and David
= 71 x 3
= 213

David's score
= 213 - 150
= 63

(b)
Gabriel's score
= 213 - 142.6
= 70.4

(c)
Ahmad's score
= 142.6 - 63
= 79.6

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

Ken's score
= 136 - 63
= 73

Answer(s): (a) 63; (b) 70.4; (c) 79.6; (d) 73