At first, Oliver had 170 more red beads than brown beads in a box. Each day, he took out 10 red beads and 5 brown beads from the box. After some time, he only had 35 brown beads left in the box.
- How many beads did Oliver take out from the box altogether?
- How many brown beads did Oliver have at first?
| |
Red beads |
Brown beads |
Comparing red beads
and brown beads at first |
170 more |
|
| Before |
10 u |
5 u + 35 |
| Change |
- 10 u |
- 5 u |
| After |
0 |
35 |
(a)
If another 170 brown beads are added into the box at first, the number of red and brown beads will be the same.
10 u = 5 u + 35 + 170
10 u - 5 u = 35 + 170
5 u = 205
1 u = 205 ÷ 5 = 41
Number of beads that Oliver took out
= 10 u + 5 u
= 15 u
= 15 x 41
= 615
(b)
Number of beads that Oliver had at first
= 615 + 35
= 650
Answer(s): (a) 615; (b) 650
