how many even multiples of 45 are there between 449 and 901 ?
450 = 10 * 45 900 = 20 * 45 the even multiples are 45 multiplied by 10 , 12 , 14 , 16 , 18 , and 20 for a total of 6 . the answer is b .
add(divide(subtract(901, 449), multiply(45, const_2)), const_1)