3 days ago, Anna had a total of 225 yellow and purple marbles. 20% of her marbles were purple marbles. Today, her cousin gave her some more marbles. As a result, her yellow marbles increased by 30%. Now, 50% of her marbles are purple marbles. How many purple marbles did her cousin give her?
| |
Purple marbles |
Yellow marbles |
Total
marbles |
| Before |
1 u |
4 u |
225 |
| Change |
+ 4.2 u |
+ 1.2 u |
|
| After |
5.2 u |
5.2 u |
|
Comparing the
yellow marbles and
purple marbles in the end |
1 |
1 |
|
20% =
20100 =
15 Purple marbles : Yellow marbles = 1 : 4
Increase in the number of yellow marbles
= 30% x 4 u
=
30100 x 4 u
= 1.2 u
50% =
50100 =
12 In the end
Purple marbles : Yellow marbles = 1 : 1
Number of marbles at first
= 4 u + 1 u
= 5 u
5 u = 225
1 u = 225 ÷ 5 = 45
Number of purple marbles that Anna received from her cousin
= 5.2 u - 1 u
= 4.2 u
= 4.2 x 45
= 189
Answer(s): 189
