The average number of beads that Bryan and Charlie have is 28.
The average number of beads that Bryan and Adam have is 58.
The number of beads that Charlie has is
25 as many as Adam.
- How many beads does Bryan have?
- How many beads does Charlie have?
- How many beads does Adam have?
(a)
Number of beads that Bryan and Charlie has
= 2 x 28
= 56
Number of beads that Bryan and Adam has
= 2 x 58
= 116
Number of beads that Charlie has = 2 u
Number of beads that Adam has = 5 u
Let the number of Bryan's beads be B.
Let the number of Charlie's beads be C.
Let the number of Adam's beads be A.
B + C = 56
B + 2 u = 56 --- (1)
B + A = 116
B + 5 u = 116 --- (2)
(2) - (1)
(B + 5 u) - (B + 2 u ) = 116 - 56
B + 5 u - B - 2 u = 60
B - B + 5 u - 2 u = 60
3 u = 60
1 u = 60 ÷ 3 = 20
Substitute 1 u = 20 into (1).
B + 2 x 20 = 56
B + 40 = 56
B = 56 - 40 = 16
Number of beads that Bryan has = 16
(b)
Number of beads that Charlie has
= 2 u
= 2 x 20
= 40
(c)
Number of beads that Adam has
= 5 u
= 5 x 20
= 100
Answer(s): (a) 16; (b) 40; (c) 100