At first, David had 120 more yellow beads than red beads in a box. Each day, he took out 10 yellow beads and 6 red beads from the box. After some time, he only had 32 red beads left in the box.
- How many beads did David take out from the box altogether?
- How many red beads did David have at first?
| |
Yellow beads |
Red beads |
Comparing yellow beads
and red beads at first |
120 more |
|
| Before |
10 u |
6 u + 32 |
| Change |
- 10 u |
- 6 u |
| After |
0 |
32 |
(a)
If another 120 red beads are added into the box at first, the number of yellow and red beads will be the same.
10 u = 6 u + 32 + 120
10 u - 6 u = 32 + 120
4 u = 152
1 u = 152 ÷ 4 = 38
Number of beads that David took out
= 10 u + 6 u
= 16 u
= 16 x 38
= 608
(b)
Number of beads that David had at first
= 608 + 32
= 640
Answer(s): (a) 608; (b) 640
