Question

A new seven-story apartment building is opening in our town. i was curious when i read that the apartments on the higher floors were more expensive, so i went to the open house. i discovered that there is only one very large apartment on the top floor. each floor has twice as many apartments as the floor above it. the lowest floor contains only one-room studio apartments that are very small. how many apartments are in this new building?

Answer 1

1+2+4+8+16+32+64=127 apartments