Round 678, to nearest ten

There are 1872 steps in a building that has 104 floors. each floor has the same number of steps. a second building has the same number of floors but 2 fewer steps between each floor. how many steps are there between each floor of the second building?

How do you find percent change? ? i will give brainliest for the bestme i don’t understand

Surface area of a right cone below with a radius of 3 and a height of 15