2 days ago, Tina had a total of 100 brown and pink coins. 40% of her coins were pink coins. Today, her older sister gave her some more coins. As a result, her brown coins increased by 20%. Now, 50% of her coins are pink coins. How many pink coins did her older sister give her?
| |
Pink coins |
Brown coins |
Total
coins |
| Before |
2 u |
3 u |
100 |
| Change |
+ 1.6 u |
+ 0.6 u |
|
| After |
3.6 u |
3.6 u |
|
Comparing the
brown coins and
pink coins in the end |
1 |
1 |
|
40% =
40100 =
25 Pink coins : Brown coins = 2 : 3
Increase in the number of brown coins
= 20% x 3 u
=
20100 x 3 u
= 0.6 u
50% =
50100 =
12 In the end
Pink coins : Brown coins = 1 : 1
Number of coins at first
= 3 u + 2 u
= 5 u
5 u = 100
1 u = 100 ÷ 5 = 20
Number of pink coins that Tina received from her older sister
= 3.6 u - 2 u
= 1.6 u
= 1.6 x 20
= 32
Answer(s): 32
