Luis, Ahmad, Tom and Tim participated in a Mathematics quiz. The average number of points scored by Luis and Ahmad was 77. The average number of points scored by Ahmad and Tim was 70.9. The average number of points scored by Luis, Ahmad and Tim was 73. The average number of points scored by Tom and Tim was 69. How many points did each of them score?

1. Tim
2. Luis
3. Ahmad
4. Tom

(a)
Total score of Luis and Ahmad
= 77 x 2
= 154

Total score of Ahmad and Tim
= 70.9 x 2
= 141.8

Total score of Luis, Ahmad and Tim
= 73 x 3
= 219

Tim's score
= 219 - 154
= 65

(b)
Luis's score
= 219 - 141.8
= 77.2

(c)
Ahmad's score
= 141.8 - 65
= 76.8

(d)
Total score of Tom and Tim
= 69 x 2
= 138

Tom's score
= 138 - 65
= 73

Answer(s): (a) 65; (b) 77.2; (c) 76.8; (d) 73