Answer: 107

Examples of writing answers:

45
3. Boy Zhenya lives in a building with a total of 100 floors. The elevator takes 1 second to travel between adjacent floors. Unfortunately, only two buttons in the elevator work: “+13 floors” and “-7 floors”. The buttons are pressed instantly.

How many seconds will it take Zhenya to get home from the 1st floor to the 24th floor? (The elevator can only travel to existing floors)