10 days ago, Cindy had a total of 240 purple and gold buttons. 25% of her buttons were gold buttons. Today, her older brother gave her some more buttons. As a result, her purple buttons increased by 10%. Now, 50% of her buttons are gold buttons. How many gold buttons did her older brother give her?
| |
Gold buttons |
Purple buttons |
Total
buttons |
| Before |
1 u |
3 u |
240 |
| Change |
+ 2.3 u |
+ 0.3 u |
|
| After |
3.3 u |
3.3 u |
|
Comparing the
purple buttons and
gold buttons in the end |
1 |
1 |
|
25% =
25100 =
14 Gold buttons : Purple buttons = 1 : 3
Increase in the number of purple buttons
= 10% x 3 u
=
10100 x 3 u
= 0.3 u
50% =
50100 =
12 In the end
Gold buttons : Purple buttons = 1 : 1
Number of buttons at first
= 3 u + 1 u
= 4 u
4 u = 240
1 u = 240 ÷ 4 = 60
Number of gold buttons that Cindy received from her older brother
= 3.3 u - 1 u
= 2.3 u
= 2.3 x 60
= 138
Answer(s): 138
