Cindy had a total of 370 gold and blue marbles. She used
35 of her gold marbles and bought another 35 blue marbles. The number of blue marbles she had then become
15 the number of gold marbles. How many less blue marbles than gold marbles did she have at first?
| |
Gold marbles |
Blue marbles |
| Before |
5x5 |
|
| Change |
- 3x5 |
+ 35 |
| After |
2x5 |
|
| Comparing marbles in the end |
5x2 |
1x2 |
| |
Gold marbles |
Blue marbles |
| Before |
25 u |
2 u - 35 |
| Change |
- 15 u |
+ 35 |
| After |
10 u |
2 u |
The number of gold marbles in the end is repeated.
LCM of 2 and 5 is 10.
Total number of gold marbles and blue marbles
= 25 u + 2 u - 35
= 27 u - 35
27 u - 35 = 370
27 u = 370 + 35
27 u = 405
1 u = 405 ÷ 27 = 15
Number of less blue marbles than gold marbles at first
= 25 u - (2 u - 35)
= 23 u + 35
= 23 x 15 + 35
= 380
Answer(s): 380
