Xiao Ming and Xiao Liang both bought the same math exercise book. Xiao Ming does 70 math problems every day, and Xiao Liang does 85 math problems every day. After 15 days, how many more problems does Xiao Liang do than Xiao Ming?
小明和小亮两人买了同一本数学练习册，小明每天做70道数学题，小亮每天做85道数学题，15天后，小亮比小明总共多做多少道题？
<gadget id="calculator">85 - 70</gadget>
<output>15</output>

<gadget id="calculator">15 * 15</gadget>
<output>225</output>

<result>225</result>