14 days ago, Jen had a total of 300 white and yellow coins. 20% of her coins were yellow coins. Today, her older sister gave her some more coins. As a result, her white coins increased by 30%. Now, 50% of her coins are yellow coins. How many yellow coins did her older sister give her?
| |
Yellow coins |
White coins |
Total
coins |
| Before |
1 u |
4 u |
300 |
| Change |
+ 4.2 u |
+ 1.2 u |
|
| After |
5.2 u |
5.2 u |
|
Comparing the
white coins and
yellow coins in the end |
1 |
1 |
|
20% =
20100 =
15 Yellow coins : White coins = 1 : 4
Increase in the number of white coins
= 30% x 4 u
=
30100 x 4 u
= 1.2 u
50% =
50100 =
12 In the end
Yellow coins : White coins = 1 : 1
Number of coins at first
= 4 u + 1 u
= 5 u
5 u = 300
1 u = 300 ÷ 5 = 60
Number of yellow coins that Jen received from her older sister
= 5.2 u - 1 u
= 4.2 u
= 4.2 x 60
= 252
Answer(s): 252
