Gillian had a total of 273 red and yellow marbles. She used
35 of her red marbles and bought another 33 yellow marbles. The number of yellow marbles she had then become
13 the number of red marbles. How many less yellow marbles than red marbles did she have at first?
| |
Red marbles |
Yellow marbles |
| Before |
5x3 |
|
| Change |
- 3x3 |
+ 33 |
| After |
2x3 |
|
| Comparing marbles in the end |
3x2 |
1x2 |
| |
Red marbles |
Yellow marbles |
| Before |
15 u |
2 u - 33 |
| Change |
- 9 u |
+ 33 |
| After |
6 u |
2 u |
The number of red marbles in the end is repeated.
LCM of 2 and 3 is 6.
Total number of red marbles and yellow marbles
= 15 u + 2 u - 33
= 17 u - 33
17 u - 33 = 273
17 u = 273 + 33
17 u = 306
1 u = 306 ÷ 17 = 18
Number of less yellow marbles than red marbles at first
= 15 u - (2 u - 33)
= 13 u + 33
= 13 x 18 + 33
= 267
Answer(s): 267
