13 days ago, Yen had a total of 160 silver and white marbles. 30% of her marbles were white marbles. Today, her father gave her some more marbles. As a result, her silver marbles increased by 25%. Now, 50% of her marbles are white marbles. How many white marbles did her father give her?
| |
White marbles |
Silver marbles |
Total
marbles |
| Before |
3 u |
7 u |
160 |
| Change |
+ 5.75 u |
+ 1.75 u |
|
| After |
8.75 u |
8.75 u |
|
Comparing the
silver marbles and
white marbles in the end |
1 |
1 |
|
30% =
30100 =
310 White marbles : Silver marbles = 3 : 7
Increase in the number of silver marbles
= 25% x 7 u
=
25100 x 7 u
= 1.75 u
50% =
50100 =
12 In the end
White marbles : Silver marbles = 1 : 1
Number of marbles at first
= 7 u + 3 u
= 10 u
10 u = 160
1 u = 160 ÷ 10 = 16
Number of white marbles that Yen received from her father
= 8.75 u - 3 u
= 5.75 u
= 5.75 x 16
= 92
Answer(s): 92
