Justin, Mark, Brandon and Seth participated in a Chinese quiz. The average number of points scored by Justin and Mark was 77. The average number of points scored by Mark and Seth was 70.3. The average number of points scored by Justin, Mark and Seth was 70. The average number of points scored by Brandon and Seth was 69. How many points did each of them score?

1. Seth
2. Justin
3. Mark
4. Brandon

(a)
Total score of Justin and Mark
= 77 x 2
= 154

Total score of Mark and Seth
= 70.3 x 2
= 140.6

Total score of Justin, Mark and Seth
= 70 x 3
= 210

Seth's score
= 210 - 154
= 56

(b)
Justin's score
= 210 - 140.6
= 69.4

(c)
Mark's score
= 140.6 - 56
= 84.6

(d)
Total score of Brandon and Seth
= 69 x 2
= 138

Brandon's score
= 138 - 56
= 82

Answer(s): (a) 56; (b) 69.4; (c) 84.6; (d) 82