8 days ago, Kylie had a total of 240 green and red cards. 25% of her cards were red cards. Today, her younger brother gave her some more cards. As a result, her green cards increased by 30%. Now, 50% of her cards are red cards. How many red cards did her younger brother give her?
| |
Red cards |
Green cards |
Total
cards |
| Before |
1 u |
3 u |
240 |
| Change |
+ 2.9 u |
+ 0.9 u |
|
| After |
3.9 u |
3.9 u |
|
Comparing the
green cards and
red cards in the end |
1 |
1 |
|
25% =
25100 =
14 Red cards : Green cards = 1 : 3
Increase in the number of green cards
= 30% x 3 u
=
30100 x 3 u
= 0.9 u
50% =
50100 =
12 In the end
Red cards : Green cards = 1 : 1
Number of cards at first
= 3 u + 1 u
= 4 u
4 u = 240
1 u = 240 ÷ 4 = 60
Number of red cards that Kylie received from her younger brother
= 3.9 u - 1 u
= 2.9 u
= 2.9 x 60
= 174
Answer(s): 174
