At first, Howard had 177 more red beads than black beads in a box. Each day, he took out 7 red beads and 2 black beads from the box. After some time, he only had 28 black beads left in the box.
- How many beads did Howard take out from the box altogether?
- How many black beads did Howard have at first?
| |
Red beads |
Black beads |
Comparing red beads
and black beads at first |
177 more |
|
| Before |
7 u |
2 u + 28 |
| Change |
- 7 u |
- 2 u |
| After |
0 |
28 |
(a)
If another 177 black beads are added into the box at first, the number of red and black beads will be the same.
7 u = 2 u + 28 + 177
7 u - 2 u = 28 + 177
5 u = 205
1 u = 205 ÷ 5 = 41
Number of beads that Howard took out
= 7 u + 2 u
= 9 u
= 9 x 41
= 369
(b)
Number of beads that Howard had at first
= 369 + 28
= 397
Answer(s): (a) 369; (b) 397
