Adam has some blue stickers and red stickers.
The number of blue stickers is increased by 10% to 99.
The number of red stickers is decreased by 20% to 60.
- How many stickers are there at first?
- How many stickers are there in the end?
|
Blue |
Green |
Before |
100% |
100% |
Change |
+ 10% |
- 20% |
After |
110% = 99 |
80% = 60 |
(a)
100% - 10% = 110%
110% of blue stickers = 99
100% of blue stickers =
99110 x 100 = 90
100% - 20% = 80%
80% of green stickers = 60
100% of green stickers =
6080 x 100 = 75
Number of stickers at first
= 100% of blue stickers + 100% of green stickers
= 90 + 75
= 165
(b)
Number of stickers in the end
= 99 + 60
= 159
Answer(s): (a) 165; (b) 159