I need help with 8 and 9

If you have 12 feet of string and you cut it into equal length of 5 inches each how much string will be left

Robin spent 25% more time on his research project than he had planned he’s been an extra h ours on the project which of the following expressions could represent the number of hours rob actually spent on the project

Binh says the point of intersections is (0,-3) which statements identify the errors binh made , check all that apply