Adam has some blue stickers and red stickers.
The number of blue stickers is decreased by 10% to 72.
The number of red stickers is decreased by 50% to 81.
- How many stickers are there at first?
- How many stickers are there in the end?
|
Blue |
Red |
Before |
100% |
100% |
Change |
- 10% |
- 50% |
After |
90% = 72 |
50% = 81 |
(a)
100% - 10% = 90%
90% of blue stickers = 72
100% of blue stickers =
7290 x 100 = 80
100% - 50% = 50%
50% of red stickers = 81
100% of red stickers =
8150 x 100 = 162
Number of stickers at first
= 100% of blue stickers + 100% of red stickers
= 80 + 162
= 242
(b)
Number of stickers in the end
= 72 + 81
= 153
Answer(s): (a) 242; (b) 153