Xandra had 5 times as many beads as erasers. After she used 135 beads and 9 erasers, there were twice as many erasers as beads.
- How many beads did Xandra have in the end?
- How many erasers did Xandra have at first?
| |
Beads |
Erasers |
Comparing beads
and erasers at first |
5 p
|
1 p
|
| Before |
1 u + 135 |
2 u + 9 |
| Change |
- 135 |
- 9 |
| After |
1 u |
2 u |
(a)
1 u + 135 = 5 p --- (1)
2 u + 9 = 1 p --- (2)
(2)
x 5
10 u + 45 = 5 p ---(3)
(3) = (1)
10 u + 45 = 1 u + 135
10 u - 1 u = 135 - 45
9 u = 90
1 u = 90 ÷ 9 = 10
Number of beads that Xandra had in the end
= 1 u
= 10
(b)
Number of erasers that Xandra had at first
= 2 u + 9
= 2 x 10 + 9
= 20 + 9
= 29
Answer(s): (a) 10; (b) 29
