Xiao Ming collected 60% pictures of famous mountains and 30% pictures of rivers. There are 90 more pictures of famous mountains than pictures of rivers. How many pictures did Xiao Ming collect in total?
小明收集的名山图片占60%，河流图片占30%，名山图片比河流图片多90张，问小明一共收集了多少张图片？
<gadget id="calculator">60 / 100</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">(3/5) - (3/10)</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">90 / (3/10)</gadget>
<output>300</output>

<result>300</result>