Alew, I agree with Keith. Plus
I know i'm not in the good thread but i need an answer:
PLEASE I think you meant to say too!
However if the question is just asking for a distance then you should just draw a straight line on the chart and using dividers/compasses/rule and the fact 1 degree of latitude = 60 nm you should get around 1080 nm. I do using both the NAT charts both using dividers and the appropriate chart scale and an inch ruler.
So on information provided don't know where the 18 lat difference comes from, sounds rubbish to me.