Adam goes to school every day. On Monday he had 6 lessons of 30 minutes each, and on Tuesday he had 3 lessons of 1 hour each. On Wednesday, Adam spent twice as much time at school as on Tuesday. How much time in total did Adam spend at school during these 3 days, in hours? Let's be accurate as possible.
On Monday Adam had 6 * 30 = 180 minutes of lessons, which is 3 hours. On Wednesday Adam spent twice as much time at school as on Tuesday, so he spent 2 * 3 = 6 hours at school. This means that during these three days Adam spent at school 3 + 3 + 6 = 12 hours.
The answer: 12.