find the average of first 5 multiples of 5 ?
"average = ( 5 + 10 + 15 + 20 + 25 ) / 5 = 15 answer is b"
divide(add(add(add(5, const_1), add(add(5, const_1), const_2)), add(subtract(5, 5), subtract(5, const_2))), 5)