Fill in the blanks in units (Eg 3 u) or unit equations (Eg 1 u + 2).
Adam, Charlie and Bryan have some beads.
After Adam's number of beads is doubled,
Charlie's number of beads is increased by 7 and
Bryan's number of beads is reduced by 5,
the ratio of the number of stickers of Adam to Charlie to Bryan becomes 6 : 7 : 2.
Let the number of stickers that Bryan has in the end be 2 u.
- Number of beads that Adam has at first = _____
- Number of beads that Charlie has at first = _____
- Number of beads that Bryan has at first = _____
- Total number of beads that they have at first = _____
|
Adam |
Charlie |
Bryan |
Before |
3 u |
7 u - 7 |
2 u + 5 |
Change |
x 2 |
+ 7 |
- 5 |
After |
6 u |
7 u |
2 u |
(a)
Change information into units.
Number of beads that Adam has at first
= 6 u ÷ 2
= 3 u
(b)
Number of beads that Charlie has at first = 7 u - 7
(c)
Number of beads that Bryan has at first = 2 u + 5
(d)
Total number of beads that they have at first
= 3 u + 7 u - 7 + 2 u + 5
= 3 u + 7 u + 2 u - 7 + 5
= 12 u - 2
Answer(s): (a) 3 u; (b) 7 u - 7; (c) 2 u + 5; (d) 12 u - 2