Question 248553
Ratio can be express as, for example, 2 to 1 or 2:1 or 2/1.
In this case, it asks for a ratio of L to W, which can be shown as L/W.
20/15 is the ratio.
or
1.33 to 1
or
1 & 1/3 to 1
.
Is 20 really one-third more than 15?  Or is is 1/4?
.
To check a change, the formula is 
{{{(new-old)/old}}}
.
{{{(20-15)/15=5/15=1/3=.33}}}