Fill in the blanks in units (Eg 3 u) or unit equations (Eg 1 u + 2).
Bryan, Charlie and Adam have some beads.
After Bryan's number of beads is doubled,
Charlie's number of beads is increased by 7 and
Adam's number of beads is reduced by 4,
the ratio of the number of stickers of Bryan to Charlie to Adam becomes 10 : 7 : 7.
Let the number of stickers that Adam has in the end be 7 u.
- Number of beads that Bryan has at first = _____
- Number of beads that Charlie has at first = _____
- Number of beads that Adam has at first = _____
- Total number of beads that they have at first = _____
|
Bryan |
Charlie |
Adam |
Before |
5 u |
7 u - 7 |
7 u + 4 |
Change |
x 2 |
+ 7 |
- 4 |
After |
10 u |
7 u |
7 u |
(a)
Change information into units.
Number of beads that Bryan has at first
= 10 u ÷ 2
= 5 u
(b)
Number of beads that Charlie has at first = 7 u - 7
(c)
Number of beads that Adam has at first = 7 u + 4
(d)
Total number of beads that they have at first
= 5 u + 7 u - 7 + 7 u + 4
= 5 u + 7 u + 7 u - 7 + 4
= 19 u - 3
Answer(s): (a) 5 u; (b) 7 u - 7; (c) 7 u + 4; (d) 19 u - 3