Adam has some blue stickers and red stickers.
The number of blue stickers is decreased by 10% to 81.
The number of red stickers is decreased by 20% to 100.
- How many stickers are there at first?
- How many stickers are there in the end?
|
Blue |
Green |
Before |
100% |
100% |
Change |
- 10% |
- 20% |
After |
90% = 81 |
80% = 100 |
(a)
100% - 10% = 90%
90% of blue stickers = 81
100% of blue stickers =
8190 x 100 = 90
100% - 20% = 80%
80% of green stickers = 100
100% of green stickers =
10080 x 100 = 125
Number of stickers at first
= 100% of blue stickers + 100% of green stickers
= 90 + 125
= 215
(b)
Number of stickers in the end
= 81 + 100
= 181
Answer(s): (a) 215; (b) 181