Gabby had a total of 246 pink and grey balls. She used
37 of her pink balls and bought another 66 grey balls. The number of grey balls she had then become
15 the number of pink balls. How many less grey balls than pink balls did she have at first?
|
Pink balls |
Grey balls |
Before |
7x5 |
|
Change |
- 3x5 |
+ 66 |
After |
4x5 |
|
Comparing balls in the end |
5x4 |
1x4 |
|
Pink balls |
Grey balls |
Before |
35 u |
4 u - 66 |
Change |
- 15 u |
+ 66 |
After |
20 u |
4 u |
The number of pink balls in the end is repeated.
LCM of 4 and 5 is 20.
Total number of pink balls and grey balls
= 35 u + 4 u - 66
= 39 u - 66
39 u - 66 = 246
39 u = 246 + 66
39 u = 312
1 u = 312 ÷ 39 = 8
Number of less grey balls than pink balls at first
= 35 u - (4 u - 66)
= 31 u + 66
= 31 x 8 + 66
= 314
Answer(s): 314