Xavier, Reggie, Vaidev and Mark participated in a Social Studies quiz. The average number of points scored by Xavier and Reggie was 75. The average number of points scored by Reggie and Mark was 70.6. The average number of points scored by Xavier, Reggie and Mark was 70. The average number of points scored by Vaidev and Mark was 69. How many points did each of them score?

1. Mark
2. Xavier
3. Reggie
4. Vaidev

(a)
Total score of Xavier and Reggie
= 75 x 2
= 150

Total score of Reggie and Mark
= 70.6 x 2
= 141.2

Total score of Xavier, Reggie and Mark
= 70 x 3
= 210

Mark's score
= 210 - 150
= 60

(b)
Xavier's score
= 210 - 141.2
= 68.8

(c)
Reggie's score
= 141.2 - 60
= 81.2

(d)
Total score of Vaidev and Mark
= 69 x 2
= 138

Vaidev's score
= 138 - 60
= 78

Answer(s): (a) 60; (b) 68.8; (c) 81.2; (d) 78