In the 99-story house there is an elevator with two buttons only. If you click on the first button, you will go 7 floors up, if you click on the second one then you go 9 floors down. How can you get from the first floor to the 72nd?

to get from the first floor to the 72nd, the person need to click 14 times the first button to get the floor 99nd and then click 3 times the second button to get the floor 72nd

Step-by-step explanation:

if the person is on the first floor and he click the first button 14 times, he will be on the floor 99nd because, 1 + (14*7) = 99, and if he click the second button 3 times then will be on the 72nd floor because, 99 - (3*9) = 99-27 = 72