steve traveled the first 2 hours of his journey at 40 mph and the last 4 hours of his journey at 80 mph . what is his average speed of travel for the entire journey ?
"average speed = total distance / total time = ( 40 * 2 + 80 * 4 ) / ( 2 + 4 ) = 400 / 6 = 66.6 answer : e"
add(divide(add(multiply(80, 4), multiply(40, 2)), add(4, 2)), subtract(divide(const_100, 4), const_0_33))