2%:3%

The ratio of 2% to 3% can be simplified by converting the percentages to fractions:

2% = 2/100 and 3% = 3/100.

The ratio is then:

\[ \frac{2/100}{3/100} = \frac{2}{3} \]

So, the ratio of 2% to 3% simplifies to 2:3.