The monthly finance charge on a charge account is 1 1/2% on the unpaid amount up to $500, and 1% on the unpaid amount over $500. What is the

1.5%*500+1%*250

=0.015*500+0.01*250

$${\mathtt{0.015}}{\mathtt{\,\times\,}}{\mathtt{500}}{\mathtt{\,\small\textbf+\,}}{\mathtt{0.01}}{\mathtt{\,\times\,}}{\mathtt{250}} = {\mathtt{10}}$$

Months charges = $10