The scale model of a skyscraper being built is 4.2 feet tall. when it is finished, the skyscraper will be 525 meters tall. what scale was used to make the model?

Which one ? is the answer and how to find this answer

I’m on question 7 it says a covered water tank is in the shape of a cylinder the tank has a 28 inch diameter and a height of 66 inches to the nearest square inch what is the surface area of the water tank

What is the length of the segment, endpoints of which are intersections of parabolas y=x2? 11 4 x? 7 4 and y=? 7 8 x2+x+ 31 8 ?