I need to run electric from the a hole I plan to drill through the basement (cinder block)to the garage that about 25 ft from the house. I live in Long Island, NY and was told that I need to dig a trench 3ft below the surface in order to stay under the frost line. The electric will be for running basic tools and a light for the outside of the garage (maybe some lighting inside as well). I'm thinking of running 3 wire BX.

Is using 3/4 inch gray pvc the right thing to run under ground? If so do I run this pipe through the Cinder block or connect it once it's on the outside?