A box contained white and grey cards. There were 60% more white cards than grey cards. When 130 more cards were poured into the box, the amount of white cards increased by 25% and the amount of grey cards increased 90%. How many cards were in the box at first?
| |
White cards |
Grey cards |
Total cards |
| Before |
8 u |
5 u |
13 u |
| Change |
+ 2 u |
+ 4.5 u |
+ 6.5 u |
| After |
10 u |
9.5 u |
19.5 u |
100% + 60% = 160%
160% =
160100 =
85Number of more white cards that were poured into the box
= 25% x 8 u
=
25100 x 8 u
= 2 u
Number of more grey cards that were poured into the box
= 90% x 5 u
=
90100 x 5 u
= 4.5 u
Total number of more cards that were poured into the box
= 2 u + 4.5 u
= 6.5 u
6.5 u = 130
1 u = 130 ÷ 6.5 = 20
Number of cards in the box at first
= 8 u + 5 u
= 13 u
= 13 x 20
= 260
Answer(s): 260
