At first, Ian had 144 more yellow beads than pink beads in a box. Each day, he took out 7 yellow beads and 3 pink beads from the box. After some time, he only had 12 pink beads left in the box.
- How many beads did Ian take out from the box altogether?
- How many pink beads did Ian have at first?
| |
Yellow beads |
Pink beads |
Comparing yellow beads
and pink beads at first |
144 more |
|
| Before |
7 u |
3 u + 12 |
| Change |
- 7 u |
- 3 u |
| After |
0 |
12 |
(a)
If another 144 pink beads are added into the box at first, the number of yellow and pink beads will be the same.
7 u = 3 u + 12 + 144
7 u - 3 u = 12 + 144
4 u = 156
1 u = 156 ÷ 4 = 39
Number of beads that Ian took out
= 7 u + 3 u
= 10 u
= 10 x 39
= 390
(b)
Number of beads that Ian had at first
= 390 + 12
= 402
Answer(s): (a) 390; (b) 402
