Mark had some coins at first. After he bought another 63 coins, he had four times as many coins as before. How many coins did Mark have at first?
| |
Coins |
| Before |
1 u |
| Change |
+ 63 |
| After |
1 u + 63 = 4 u |
Number of coins after he bought = 1 u + 63
Number of coins that is four times as many coins as before = 4 x 1 u = 4 u
4 u = 1 u + 63
4 u - 1 u = 63
3 u = 63
1 u = 63 ÷ 3 = 21
Number of stickers that Kim had at first
= 1 u
= 21
Answer(s): 21
