Answer
$0.15$
Work Step by Step
If we can write a fraction so that its denominator is one of 10,100, 1000,...,
we can easily write it as a decimal number
Using the fact that $20\cdot 5=100,$
$\displaystyle \frac{3}{20}=\frac{3\cdot 5}{20\cdot 5}=\frac{15}{100 }$
We write this as a decimal number with one digit after the decimal point:
$= 0.15$
