how many even multiples of 25 are there between 249 and 501 ?
"250 = 10 * 25 500 = 20 * 25 the even multiples are 25 multiplied by 10 , 12 , 14 , 16 , 18 , and 20 for a total of 6 . the answer is b ."
add(divide(subtract(501, 249), multiply(25, const_2)), const_1)