Lizzy: John buys 2 packs of index cards for all his students. He has 6 classes and 30 students in each class. How many packs did he buy?.
Me: Hmmm, let me think. I think this is the detailed solution:
John has 6 * 30 = 180 students. So he bought 180 * 2 = 360 packs. Final answer: 360.