9 divided by 72 = 0.125 0.125 is the weight of one book 0.125 times 80 = 10kg. So 80 books weight 10kg. 72 divided by 9 = 8 books make up 1 kg. 8 times 6 =48
hi glad to help so what you do is basically divide 171 by 12 and you get 14.25 so the unit rate is 14.25 per hour hope i helped plz can i have brainliest
