steve traveled the first 2 hours of his journey at 50 mph and the last 3 hours of his journey at 80 mph . what is his average speed of travel for the entire journey ?
"average speed = total distance / total time = ( 50 * 2 + 80 * 3 ) / ( 2 + 3 ) = 68 ans : a"
add(divide(add(multiply(80, 3), multiply(50, 2)), add(3, 2)), subtract(divide(const_100, 3), const_0_33))