Adam has some blue stickers and red stickers.
The number of blue stickers is decreased by 40% to 78.
The number of red stickers is decreased by 20% to 80.
- How many stickers are there at first?
- How many stickers are there in the end?
|
Red |
Blue |
Before |
100% |
100% |
Change |
- 40% |
- 20% |
After |
60% = 78 |
80% = 80 |
(a)
100% - 40% = 60%
60% of red stickers = 78
100% of red stickers =
7860 x 100 = 130
100% - 20% = 80%
80% of blue stickers = 80
100% of blue stickers =
8080 x 100 = 100
Number of stickers at first
= 100% of red stickers + 100% of blue stickers
= 130 + 100
= 230
(b)
Number of stickers in the end
= 78 + 80
= 158
Answer(s): (a) 230; (b) 158