The tax $= 30\; \text{paise} = Rs.\;0.3.$ The tax is $6\%.$
$Rs.\;0.3$ is $6\%$ of the taxable item.
Therefore, cost of taxable item $ = \dfrac{0.3\times 100}{6} = Rs.\;5$
$\therefore$ The cost of the tax free items $=25−(0.3+5) = Rs.\;19.70$
So, the correct answer is $(B).$