Adam has some blue stickers and red stickers.
The number of blue stickers is increased by 20% to 72.
The number of red stickers is decreased by 40% to 51.
- How many stickers are there at first?
- How many stickers are there in the end?
|
Blue |
Red |
Before |
100% |
100% |
Change |
+ 20% |
- 40% |
After |
120% = 72 |
60% = 51 |
(a)
100% - 20% = 120%
120% of blue stickers = 72
100% of blue stickers =
72120 x 100 = 60
100% - 40% = 60%
60% of red stickers = 51
100% of red stickers =
5160 x 100 = 85
Number of stickers at first
= 100% of blue stickers + 100% of red stickers
= 60 + 85
= 145
(b)
Number of stickers in the end
= 72 + 51
= 123
Answer(s): (a) 145; (b) 123