At first, Lee had 123 more red beads than blue beads in a box. Each day, he took out 5 red beads and 2 blue beads from the box. After some time, he only had 18 blue beads left in the box.
- How many beads did Lee take out from the box altogether?
- How many blue beads did Lee have at first?
| |
Red beads |
Blue beads |
Comparing red beads
and blue beads at first |
123 more |
|
| Before |
5 u |
2 u + 18 |
| Change |
- 5 u |
- 2 u |
| After |
0 |
18 |
(a)
If another 123 blue beads are added into the box at first, the number of red and blue beads will be the same.
5 u = 2 u + 18 + 123
5 u - 2 u = 18 + 123
3 u = 141
1 u = 141 ÷ 3 = 47
Number of beads that Lee took out
= 5 u + 2 u
= 7 u
= 7 x 47
= 329
(b)
Number of beads that Lee had at first
= 329 + 18
= 347
Answer(s): (a) 329; (b) 347
