Adam has some blue stickers and red stickers.
The number of blue stickers is increased by 20% to 90.
The number of red stickers is decreased by 10% to 63.
- How many stickers are there at first?
- How many stickers are there in the end?
|
Green |
Blue |
Before |
100% |
100% |
Change |
+ 20% |
- 10% |
After |
120% = 90 |
90% = 63 |
(a)
100% - 20% = 120%
120% of green stickers = 90
100% of green stickers =
90120 x 100 = 75
100% - 10% = 90%
90% of blue stickers = 63
100% of blue stickers =
6390 x 100 = 70
Number of stickers at first
= 100% of green stickers + 100% of blue stickers
= 75 + 70
= 145
(b)
Number of stickers in the end
= 90 + 63
= 153
Answer(s): (a) 145; (b) 153