The answer is that the man is a dwarf / short in stature, and he can’t reach the 10th-floor button in the elevator. He used the umbrella
Another puzzle A man lives on the 10th floor. Every morning, he takes the elevator down to the ground floor and goes to work. When he returns, he takes the elevator up to the **7th floor, then walks up the stairs to the 10th. But when it rains, he takes the elevator all the way to the 10th floor. Why? 👀 Reward 1000XEC answer is subject to my choice See you guys in few hours lol