14 days ago, Gwen had a total of 200 pink and silver marbles. 25% of her marbles were silver marbles. Today, her father gave her some more marbles. As a result, her pink marbles increased by 40%. Now, 50% of her marbles are silver marbles. How many silver marbles did her father give her?
| |
Silver marbles |
Pink marbles |
Total
marbles |
| Before |
1 u |
3 u |
200 |
| Change |
+ 3.2 u |
+ 1.2 u |
|
| After |
4.2 u |
4.2 u |
|
Comparing the
pink marbles and
silver marbles in the end |
1 |
1 |
|
25% =
25100 =
14 Silver marbles : Pink marbles = 1 : 3
Increase in the number of pink marbles
= 40% x 3 u
=
40100 x 3 u
= 1.2 u
50% =
50100 =
12 In the end
Silver marbles : Pink marbles = 1 : 1
Number of marbles at first
= 3 u + 1 u
= 4 u
4 u = 200
1 u = 200 ÷ 4 = 50
Number of silver marbles that Gwen received from her father
= 4.2 u - 1 u
= 3.2 u
= 3.2 x 50
= 160
Answer(s): 160
