Mark, Daniel, John and Billy participated in a Mathematics quiz. The average number of points scored by Mark and Daniel was 74. The average number of points scored by Daniel and Billy was 70.4. The average number of points scored by Mark, Daniel and Billy was 71. The average number of points scored by John and Billy was 65. How many points did each of them score?

1. Billy
2. Mark
3. Daniel
4. John

(a)
Total score of Mark and Daniel
= 74 x 2
= 148

Total score of Daniel and Billy
= 70.4 x 2
= 140.8

Total score of Mark, Daniel and Billy
= 71 x 3
= 213

Billy's score
= 213 - 148
= 65

(b)
Mark's score
= 213 - 140.8
= 72.2

(c)
Daniel's score
= 140.8 - 65
= 75.8

(d)
Total score of John and Billy
= 65 x 2
= 130

John's score
= 130 - 65
= 65

Answer(s): (a) 65; (b) 72.2; (c) 75.8; (d) 65