Give the step-by-step reasoning process and then the final answer. John buys 10 packs of magic cards. Each pack has 20 cards and 1/4 of those cards are uncommon. How many uncommon cards did he get?
Each pack has 20 / 4 = 5 uncommons. So he got 10 * 5 = 50 uncommons.
The final answer: 50.