Adam has 390 green stickers and blue stickers.
30% of them are green stickers and the rest are blue stickers.
When Adam buys more green stickers,
70% of the stickers are green stickers.
How many stickers does Adam buy?
|
Green |
Blue |
Before |
3 x 3 = 9 u |
7 x 3 = 21 u |
Change |
+ ? |
No change |
After |
7 x 7 = 49 u |
3 x 7 = 21 u |
30% =
30100 =
31070% =
70100 =
710 The number of blue stickers remains unchanged.
Make the number of blue stickers the same using the LCM of 7 and 3.
LCM of 7 and 3 = 21
Total number of stickers at first
= 9 u + 21 u
= 30 u
30 u = 390
1 u = 390 ÷ 30 = 13
Number of stickers that Adam buys
= 49 u - 9 u
= 40 u
= 40 x 13
= 520
Answer(s): 520