Tammy had a total of 408 yellow and white marbles. She used
35 of her yellow marbles and bought another 68 white marbles. The number of white marbles she had then become
13 the number of yellow marbles. How many less white marbles than yellow marbles did she have at first?
| |
Yellow marbles |
White marbles |
| Before |
5x3 |
|
| Change |
- 3x3 |
+ 68 |
| After |
2x3 |
|
| Comparing marbles in the end |
3x2 |
1x2 |
| |
Yellow marbles |
White marbles |
| Before |
15 u |
2 u - 68 |
| Change |
- 9 u |
+ 68 |
| After |
6 u |
2 u |
The number of yellow marbles in the end is repeated.
LCM of 2 and 3 is 6.
Total number of yellow marbles and white marbles
= 15 u + 2 u - 68
= 17 u - 68
17 u - 68 = 408
17 u = 408 + 68
17 u = 476
1 u = 476 ÷ 17 = 28
Number of less white marbles than yellow marbles at first
= 15 u - (2 u - 68)
= 13 u + 68
= 13 x 28 + 68
= 432
Answer(s): 432
