Adam has some blue stickers and red stickers.
The number of blue stickers is decreased by 25% to 90.
The number of red stickers is decreased by 10% to 81.
- How many stickers are there at first?
- How many stickers are there in the end?
|
Red |
Green |
Before |
100% |
100% |
Change |
- 25% |
- 10% |
After |
75% = 90 |
90% = 81 |
(a)
100% - 25% = 75%
75% of red stickers = 90
100% of red stickers =
9075 x 100 = 120
100% - 10% = 90%
90% of green stickers = 81
100% of green stickers =
8190 x 100 = 90
Number of stickers at first
= 100% of red stickers + 100% of green stickers
= 120 + 90
= 210
(b)
Number of stickers in the end
= 90 + 81
= 171
Answer(s): (a) 210; (b) 171