There was an equal number of brown and silver balls in a packet at first. After 13 silver balls were taken out and 39 brown balls were added into the packet, there was
13 as many silver balls as brown balls. Find the number of silver balls in the packet at first.
| |
Brown balls |
Silver balls |
| Before |
3 u - 39 |
1 u + 13 |
| Change |
+ 39 |
- 13 |
| After |
3 u |
1 u |
The number of brown and silver balls in the packet is the same at first.
3 u - 39 = 1 u + 13
3 u - 1 u = 13 + 39
2 u = 52
1 u = 52 ÷ 2 = 26
Number of silver balls at first
= 1 u + 13
= 26 + 13
= 39
Answer(s)39
