5 days ago, Dana had a total of 225 purple and brown buttons. 20% of her buttons were brown buttons. Today, her older brother gave her some more buttons. As a result, her purple buttons increased by 30%. Now, 50% of her buttons are brown buttons. How many brown buttons did her older brother give her?
| |
Brown buttons |
Purple buttons |
Total
buttons |
| Before |
1 u |
4 u |
225 |
| Change |
+ 4.2 u |
+ 1.2 u |
|
| After |
5.2 u |
5.2 u |
|
Comparing the
purple buttons and
brown buttons in the end |
1 |
1 |
|
20% =
20100 =
15 Brown buttons : Purple buttons = 1 : 4
Increase in the number of purple buttons
= 30% x 4 u
=
30100 x 4 u
= 1.2 u
50% =
50100 =
12 In the end
Brown buttons : Purple buttons = 1 : 1
Number of buttons at first
= 4 u + 1 u
= 5 u
5 u = 225
1 u = 225 ÷ 5 = 45
Number of brown buttons that Dana received from her older brother
= 5.2 u - 1 u
= 4.2 u
= 4.2 x 45
= 189
Answer(s): 189
