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 20% to 68.
- How many stickers are there at first?
- How many stickers are there in the end?
|
Blue |
Red |
Before |
100% |
100% |
Change |
- 10% |
- 20% |
After |
90% = 72 |
80% = 68 |
(a)
100% - 10% = 90%
90% of blue stickers = 72
100% of blue stickers =
7290 x 100 = 80
100% - 20% = 80%
80% of red stickers = 68
100% of red stickers =
6880 x 100 = 85
Number of stickers at first
= 100% of blue stickers + 100% of red stickers
= 80 + 85
= 165
(b)
Number of stickers in the end
= 72 + 68
= 140
Answer(s): (a) 165; (b) 140