Min had a total of 418 silver and gold balls. She used
35 of her silver balls and bought another 68 gold balls. The number of gold balls she had then become
15 the number of silver balls. How many less gold balls than silver balls did she have at first?
|
Silver balls |
Gold balls |
Before |
5x5 |
|
Change |
- 3x5 |
+ 68 |
After |
2x5 |
|
Comparing balls in the end |
5x2 |
1x2 |
|
Silver balls |
Gold balls |
Before |
25 u |
2 u - 68 |
Change |
- 15 u |
+ 68 |
After |
10 u |
2 u |
The number of silver balls in the end is repeated.
LCM of 2 and 5 is 10.
Total number of silver balls and gold balls
= 25 u + 2 u - 68
= 27 u - 68
27 u - 68 = 418
27 u = 418 + 68
27 u = 486
1 u = 486 ÷ 27 = 18
Number of less gold balls than silver balls at first
= 25 u - (2 u - 68)
= 23 u + 68
= 23 x 18 + 68
= 482
Answer(s): 482