Adam has some blue stickers and red stickers.
The number of blue stickers is decreased by 20% to 100.
The number of red stickers is decreased by 10% to 72.
- How many stickers are there at first?
- How many stickers are there in the end?
|
Green |
Blue |
Before |
100% |
100% |
Change |
- 20% |
- 10% |
After |
80% = 100 |
90% = 72 |
(a)
100% - 20% = 80%
80% of green stickers = 100
100% of green stickers =
10080 x 100 = 125
100% - 10% = 90%
90% of blue stickers = 72
100% of blue stickers =
7290 x 100 = 80
Number of stickers at first
= 100% of green stickers + 100% of blue stickers
= 125 + 80
= 205
(b)
Number of stickers in the end
= 100 + 72
= 172
Answer(s): (a) 205; (b) 172