At first, Julian had 122 more purple beads than blue beads in a box. Each day, he took out 7 purple beads and 4 blue beads from the box. After some time, he only had 13 blue beads left in the box.
- How many beads did Julian take out from the box altogether?
- How many blue beads did Julian have at first?
| |
Purple beads |
Blue beads |
Comparing purple beads
and blue beads at first |
122 more |
|
| Before |
7 u |
4 u + 13 |
| Change |
- 7 u |
- 4 u |
| After |
0 |
13 |
(a)
If another 122 blue beads are added into the box at first, the number of purple and blue beads will be the same.
7 u = 4 u + 13 + 122
7 u - 4 u = 13 + 122
3 u = 135
1 u = 135 ÷ 3 = 45
Number of beads that Julian took out
= 7 u + 4 u
= 11 u
= 11 x 45
= 495
(b)
Number of beads that Julian had at first
= 495 + 13
= 508
Answer(s): (a) 495; (b) 508
