70% of 23 is 16.1
[tex]0.7 \times 23[/tex]
Just for your note; to understand how to derive an answer to a question like this, here:
is/of=%/100
x/23=70/100
100x=1610
100x/100=1610/100
x=16.1
Thus, 16.1 is 70% of 23.