Riddle:
How can you cut a cheese round into 8 pieces with only three cuts?
Answer: First you cut the cylinder lengthwise. With the two pieces stacked end to end, you cut the cheese into quarters with two cuts. The result is three cuts and 8 pieces of cheese. See the image below for three cuts needed to divide a cheese round into eight pieces.
Riddle:
My last five letters refer to a raised line on the surface of something; my whole refer to a thin tube containing ink inside a pen. My first three & four letters both refer to vehicles. I am a word of nine letters. What Word am I?