Answer:
209 : 40 or 5.225 : 1
Step-by-step explanation:
Your calculator can tell you the ratio 8.36/1.60 is 5.225. Writing that decimal as a fraction, you can factor out 25 to get ...
8.36 : 1.6 = 5.225 : 1 = 5225 : 1000 = (25)(209) : (25)(40) = 209 : 40
Divide

by 5. Or multiply it by 1/5.
You get - 56/25 or

pounds per month.
The sum of the first n natural numbers and 0=
n*(n+1)/2