7 days ago, Jade had a total of 125 yellow and blue cards. 40% of her cards were blue cards. Today, her older brother gave her some more cards. As a result, her yellow cards increased by 20%. Now, 50% of her cards are blue cards. How many blue cards did her older brother give her?
| |
Blue cards |
Yellow cards |
Total
cards |
| Before |
2 u |
3 u |
125 |
| Change |
+ 1.6 u |
+ 0.6 u |
|
| After |
3.6 u |
3.6 u |
|
Comparing the
yellow cards and
blue cards in the end |
1 |
1 |
|
40% =
40100 =
25 Blue cards : Yellow cards = 2 : 3
Increase in the number of yellow cards
= 20% x 3 u
=
20100 x 3 u
= 0.6 u
50% =
50100 =
12 In the end
Blue cards : Yellow cards = 1 : 1
Number of cards at first
= 3 u + 2 u
= 5 u
5 u = 125
1 u = 125 ÷ 5 = 25
Number of blue cards that Jade received from her older brother
= 3.6 u - 2 u
= 1.6 u
= 1.6 x 25
= 40
Answer(s): 40
