6 days ago, Lynn had a total of 160 blue and silver cards. 40% of her cards were silver cards. Today, her grandmother gave her some more cards. As a result, her blue cards increased by 25%. Now, 50% of her cards are silver cards. How many silver cards did her grandmother give her?
| |
Silver cards |
Blue cards |
Total
cards |
| Before |
2 u |
3 u |
160 |
| Change |
+ 1.75 u |
+ 0.75 u |
|
| After |
3.75 u |
3.75 u |
|
Comparing the
blue cards and
silver cards in the end |
1 |
1 |
|
40% =
40100 =
25 Silver cards : Blue cards = 2 : 3
Increase in the number of blue cards
= 25% x 3 u
=
25100 x 3 u
= 0.75 u
50% =
50100 =
12 In the end
Silver cards : Blue cards = 1 : 1
Number of cards at first
= 3 u + 2 u
= 5 u
5 u = 160
1 u = 160 ÷ 5 = 32
Number of silver cards that Lynn received from her grandmother
= 3.75 u - 2 u
= 1.75 u
= 1.75 x 32
= 56
Answer(s): 56
