Tina had a total of 269 blue and yellow marbles. She used
35 of her blue marbles and bought another 55 yellow marbles. The number of yellow marbles she had then become
15 the number of blue marbles. How many less yellow marbles than blue marbles did she have at first?
| |
Blue marbles |
Yellow marbles |
| Before |
5x5 |
|
| Change |
- 3x5 |
+ 55 |
| After |
2x5 |
|
| Comparing marbles in the end |
5x2 |
1x2 |
| |
Blue marbles |
Yellow marbles |
| Before |
25 u |
2 u - 55 |
| Change |
- 15 u |
+ 55 |
| After |
10 u |
2 u |
The number of blue marbles in the end is repeated.
LCM of 2 and 5 is 10.
Total number of blue marbles and yellow marbles
= 25 u + 2 u - 55
= 27 u - 55
27 u - 55 = 269
27 u = 269 + 55
27 u = 324
1 u = 324 ÷ 27 = 12
Number of less yellow marbles than blue marbles at first
= 25 u - (2 u - 55)
= 23 u + 55
= 23 x 12 + 55
= 331
Answer(s): 331
