At first, Carl had 107 more purple beads than blue beads in a box. Each day, he took out 10 purple beads and 6 blue beads from the box. After some time, he only had 21 blue beads left in the box.
- How many beads did Carl take out from the box altogether?
- How many blue beads did Carl have at first?
| |
Purple beads |
Blue beads |
Comparing purple beads
and blue beads at first |
107 more |
|
| Before |
10 u |
6 u + 21 |
| Change |
- 10 u |
- 6 u |
| After |
0 |
21 |
(a)
If another 107 blue beads are added into the box at first, the number of purple and blue beads will be the same.
10 u = 6 u + 21 + 107
10 u - 6 u = 21 + 107
4 u = 128
1 u = 128 ÷ 4 = 32
Number of beads that Carl took out
= 10 u + 6 u
= 16 u
= 16 x 32
= 512
(b)
Number of beads that Carl had at first
= 512 + 21
= 533
Answer(s): (a) 512; (b) 533
