Dana had a total of 412 gold and brown balls. She used
37 of her gold balls and bought another 63 brown balls. The number of brown balls she had then become
13 the number of gold balls. How many less brown balls than gold balls did she have at first?
|
Gold balls |
Brown balls |
Before |
7x3 |
|
Change |
- 3x3 |
+ 63 |
After |
4x3 |
|
Comparing balls in the end |
3x4 |
1x4 |
|
Gold balls |
Brown balls |
Before |
21 u |
4 u - 63 |
Change |
- 9 u |
+ 63 |
After |
12 u |
4 u |
The number of gold balls in the end is repeated.
LCM of 4 and 3 is 12.
Total number of gold balls and brown balls
= 21 u + 4 u - 63
= 25 u - 63
25 u - 63 = 412
25 u = 412 + 63
25 u = 475
1 u = 475 ÷ 25 = 19
Number of less brown balls than gold balls at first
= 21 u - (4 u - 63)
= 17 u + 63
= 17 x 19 + 63
= 386
Answer(s): 386