Julie had a total of 435 black and yellow marbles. She used
45 of her black marbles and bought another 59 yellow marbles. The number of yellow marbles she had then become
15 the number of black marbles. How many less yellow marbles than black marbles did she have at first?
| |
Black marbles |
Yellow marbles |
| Before |
5x5 |
|
| Change |
- 4x5 |
+ 59 |
| After |
1x5 |
|
| Comparing marbles in the end |
5x1 |
1x1 |
| |
Black marbles |
Yellow marbles |
| Before |
25 u |
1 u - 59 |
| Change |
- 20 u |
+ 59 |
| After |
5 u |
1 u |
The number of black marbles in the end is repeated.
LCM of 1 and 5 is 5.
Total number of black marbles and yellow marbles
= 25 u + 1 u - 59
= 26 u - 59
26 u - 59 = 435
26 u = 435 + 59
26 u = 494
1 u = 494 ÷ 26 = 19
Number of less yellow marbles than black marbles at first
= 25 u - (1 u - 59)
= 24 u + 59
= 24 x 19 + 59
= 515
Answer(s): 515
