7 days ago, Anna had a total of 200 gold and blue cards. 25% of her cards were blue cards. Today, her cousin gave her some more cards. As a result, her gold cards increased by 20%. Now, 50% of her cards are blue cards. How many blue cards did her cousin give her?
| |
Blue cards |
Gold cards |
Total
cards |
| Before |
1 u |
3 u |
200 |
| Change |
+ 2.6 u |
+ 0.6 u |
|
| After |
3.6 u |
3.6 u |
|
Comparing the
gold cards and
blue cards in the end |
1 |
1 |
|
25% =
25100 =
14 Blue cards : Gold cards = 1 : 3
Increase in the number of gold cards
= 20% x 3 u
=
20100 x 3 u
= 0.6 u
50% =
50100 =
12 In the end
Blue cards : Gold cards = 1 : 1
Number of cards at first
= 3 u + 1 u
= 4 u
4 u = 200
1 u = 200 ÷ 4 = 50
Number of blue cards that Anna received from her cousin
= 3.6 u - 1 u
= 2.6 u
= 2.6 x 50
= 130
Answer(s): 130
