10 days ago, Opal had a total of 120 purple and pink erasers. 25% of her erasers were pink erasers. Today, her auntie gave her some more erasers. As a result, her purple erasers increased by 40%. Now, 50% of her erasers are pink erasers. How many pink erasers did her auntie give her?
| |
Pink erasers |
Purple erasers |
Total
erasers |
| Before |
1 u |
3 u |
120 |
| Change |
+ 3.2 u |
+ 1.2 u |
|
| After |
4.2 u |
4.2 u |
|
Comparing the
purple erasers and
pink erasers in the end |
1 |
1 |
|
25% =
25100 =
14 Pink erasers : Purple erasers = 1 : 3
Increase in the number of purple erasers
= 40% x 3 u
=
40100 x 3 u
= 1.2 u
50% =
50100 =
12 In the end
Pink erasers : Purple erasers = 1 : 1
Number of erasers at first
= 3 u + 1 u
= 4 u
4 u = 120
1 u = 120 ÷ 4 = 30
Number of pink erasers that Opal received from her auntie
= 4.2 u - 1 u
= 3.2 u
= 3.2 x 30
= 96
Answer(s): 96
