Lizzy: Julia's internet speed is 20 MBps (megabytes per second). How many songs she can download in half an hour if the size per song is 5MB?.
Me: Hmmm, let me think. I think this is the detailed solution:
1 hour has 60 minutes, therefore 1 / 2 hour has 1 / 2 * 60 = 30 minutes. 1 minute has 60 seconds, therefore 30 minutes has 30 * 60 = 1800 seconds. If Julia's internet speed is 20MBps and each song has a size of 5MB, then it would take 5 / 20 = 1 / 4 seconds to download one song. If it takes 1 / 4 seconds to download 1 song, then in 1800 seconds, Julia could download 1800 / (1 / 4) = 1800 * 4 = 7200 songs. Final answer: 7200.