Whoever gives right answer gets brainlest

Atheater wants to build movable steps that they can use to go on and off the stage. they want the steps to have enough space inside so they can also be used to store props. how much space is inside the steps?

Anyone? 15m is what percent of 60m; 3m; 30m; 1.5 km?

Which steps could be part of the process in algebraically solving the system of equations, y+5x=x^2+10 and y=4x-10