NEED HELP ON THIS QUESTION!!!!! from module 0, 3rd quiz, problem 13

I don't know how prof. Loh get the ratio of 1.1 when 1.1 is a number, not a ratio?

@victorioussheep
1.1 is here is the same as 1:1.1. 
@rz923 I don't how Pro. Loh got to the ratio of 1:1.1. Can you explain this to me?

@victorioussheep The current diameter is 33 inches, and the normal diameter is 30 inches. The ratio between the two is then
$$ \frac{33}{30}=\frac{11}{10}=1.1 $$Hope this helps

@quacker88 this helps me a lot! Thank you so much!