4 days ago, Vanessa had a total of 125 pink and red buttons. 20% of her buttons were red buttons. Today, her cousin gave her some more buttons. As a result, her pink buttons increased by 10%. Now, 50% of her buttons are red buttons. How many red buttons did her cousin give her?
| |
Red buttons |
Pink buttons |
Total
buttons |
| Before |
1 u |
4 u |
125 |
| Change |
+ 3.4 u |
+ 0.4 u |
|
| After |
4.4 u |
4.4 u |
|
Comparing the
pink buttons and
red buttons in the end |
1 |
1 |
|
20% =
20100 =
15 Red buttons : Pink buttons = 1 : 4
Increase in the number of pink buttons
= 10% x 4 u
=
10100 x 4 u
= 0.4 u
50% =
50100 =
12 In the end
Red buttons : Pink buttons = 1 : 1
Number of buttons at first
= 4 u + 1 u
= 5 u
5 u = 125
1 u = 125 ÷ 5 = 25
Number of red buttons that Vanessa received from her cousin
= 4.4 u - 1 u
= 3.4 u
= 3.4 x 25
= 85
Answer(s): 85
