2 days ago, Natalie had a total of 160 white and purple cards. 40% of her cards were purple cards. Today, her younger brother gave her some more cards. As a result, her white cards increased by 25%. Now, 50% of her cards are purple cards. How many purple cards did her younger brother give her?
| |
Purple cards |
White cards |
Total
cards |
| Before |
2 u |
3 u |
160 |
| Change |
+ 1.75 u |
+ 0.75 u |
|
| After |
3.75 u |
3.75 u |
|
Comparing the
white cards and
purple cards in the end |
1 |
1 |
|
40% =
40100 =
25 Purple cards : White cards = 2 : 3
Increase in the number of white cards
= 25% x 3 u
=
25100 x 3 u
= 0.75 u
50% =
50100 =
12 In the end
Purple cards : White cards = 1 : 1
Number of cards at first
= 3 u + 2 u
= 5 u
5 u = 160
1 u = 160 ÷ 5 = 32
Number of purple cards that Natalie received from her younger brother
= 3.75 u - 2 u
= 1.75 u
= 1.75 x 32
= 56
Answer(s): 56
