4 days ago, Opal had a total of 275 brown and pink coins. 20% of her coins were pink coins. Today, her younger sister gave her some more coins. As a result, her brown coins increased by 10%. Now, 50% of her coins are pink coins. How many pink coins did her younger sister give her?
| |
Pink coins |
Brown coins |
Total
coins |
| Before |
1 u |
4 u |
275 |
| Change |
+ 3.4 u |
+ 0.4 u |
|
| After |
4.4 u |
4.4 u |
|
Comparing the
brown coins and
pink coins in the end |
1 |
1 |
|
20% =
20100 =
15 Pink coins : Brown coins = 1 : 4
Increase in the number of brown coins
= 10% x 4 u
=
10100 x 4 u
= 0.4 u
50% =
50100 =
12 In the end
Pink coins : Brown coins = 1 : 1
Number of coins at first
= 4 u + 1 u
= 5 u
5 u = 275
1 u = 275 ÷ 5 = 55
Number of pink coins that Opal received from her younger sister
= 4.4 u - 1 u
= 3.4 u
= 3.4 x 55
= 187
Answer(s): 187
