At first, Oscar had 108 more blue beads than red beads in a box. Each day, he took out 10 blue beads and 5 red beads from the box. After some time, he only had 32 red beads left in the box.
- How many beads did Oscar take out from the box altogether?
- How many red beads did Oscar have at first?
| |
Blue beads |
Red beads |
Comparing blue beads
and red beads at first |
108 more |
|
| Before |
10 u |
5 u + 32 |
| Change |
- 10 u |
- 5 u |
| After |
0 |
32 |
(a)
If another 108 red beads are added into the box at first, the number of blue and red beads will be the same.
10 u = 5 u + 32 + 108
10 u - 5 u = 32 + 108
5 u = 140
1 u = 140 ÷ 5 = 28
Number of beads that Oscar took out
= 10 u + 5 u
= 15 u
= 15 x 28
= 420
(b)
Number of beads that Oscar had at first
= 420 + 32
= 452
Answer(s): (a) 420; (b) 452
