At first, Andy had 111 more red beads than purple beads in a box. Each day, he took out 6 red beads and 3 purple beads from the box. After some time, he only had 30 purple beads left in the box.
- How many beads did Andy take out from the box altogether?
- How many purple beads did Andy have at first?
| |
Red beads |
Purple beads |
Comparing red beads
and purple beads at first |
111 more |
|
| Before |
6 u |
3 u + 30 |
| Change |
- 6 u |
- 3 u |
| After |
0 |
30 |
(a)
If another 111 purple beads are added into the box at first, the number of red and purple beads will be the same.
6 u = 3 u + 30 + 111
6 u - 3 u = 30 + 111
3 u = 141
1 u = 141 ÷ 3 = 47
Number of beads that Andy took out
= 6 u + 3 u
= 9 u
= 9 x 47
= 423
(b)
Number of beads that Andy had at first
= 423 + 30
= 453
Answer(s): (a) 423; (b) 453
