4 days ago, Winnie had a total of 100 purple and green cards. 40% of her cards were green cards. Today, her grandmother gave her some more cards. As a result, her purple cards increased by 20%. Now, 50% of her cards are green cards. How many green cards did her grandmother give her?
| |
Green cards |
Purple cards |
Total
cards |
| Before |
2 u |
3 u |
100 |
| Change |
+ 1.6 u |
+ 0.6 u |
|
| After |
3.6 u |
3.6 u |
|
Comparing the
purple cards and
green cards in the end |
1 |
1 |
|
40% =
40100 =
25 Green cards : Purple cards = 2 : 3
Increase in the number of purple cards
= 20% x 3 u
=
20100 x 3 u
= 0.6 u
50% =
50100 =
12 In the end
Green cards : Purple cards = 1 : 1
Number of cards at first
= 3 u + 2 u
= 5 u
5 u = 100
1 u = 100 ÷ 5 = 20
Number of green cards that Winnie received from her grandmother
= 3.6 u - 2 u
= 1.6 u
= 1.6 x 20
= 32
Answer(s): 32
