Adam has some blue stickers and red stickers.
The number of blue stickers is increased by 20% to 66.
The number of red stickers is decreased by 10% to 90.
- How many stickers are there at first?
- How many stickers are there in the end?
|
Blue |
Red |
Before |
100% |
100% |
Change |
+ 20% |
- 10% |
After |
120% = 66 |
90% = 90 |
(a)
100% - 20% = 120%
120% of blue stickers = 66
100% of blue stickers =
66120 x 100 = 55
100% - 10% = 90%
90% of red stickers = 90
100% of red stickers =
9090 x 100 = 100
Number of stickers at first
= 100% of blue stickers + 100% of red stickers
= 55 + 100
= 155
(b)
Number of stickers in the end
= 66 + 90
= 156
Answer(s): (a) 155; (b) 156