Diana had a total of 265 yellow and grey marbles. She used
37 of her yellow marbles and bought another 47 grey marbles. The number of grey marbles she had then become
15 the number of yellow marbles. How many less grey marbles than yellow marbles did she have at first?
| |
Yellow marbles |
Grey marbles |
| Before |
7x5 |
|
| Change |
- 3x5 |
+ 47 |
| After |
4x5 |
|
| Comparing marbles in the end |
5x4 |
1x4 |
| |
Yellow marbles |
Grey marbles |
| Before |
35 u |
4 u - 47 |
| Change |
- 15 u |
+ 47 |
| After |
20 u |
4 u |
The number of yellow marbles in the end is repeated.
LCM of 4 and 5 is 20.
Total number of yellow marbles and grey marbles
= 35 u + 4 u - 47
= 39 u - 47
39 u - 47 = 265
39 u = 265 + 47
39 u = 312
1 u = 312 ÷ 39 = 8
Number of less grey marbles than yellow marbles at first
= 35 u - (4 u - 47)
= 31 u + 47
= 31 x 8 + 47
= 295
Answer(s): 295
