The school library purchased 180 science and technology books, 105 less than the three times the number of story books purchased. How many story books were purchased? (Solution of column equation)
学校图书馆购进科技书180本，比购进故事书本数的3倍少105本，购进故事书多少本？(列方程解)
<gadget id="calculator">180 + 105</gadget>
<output>285</output>

<gadget id="calculator">285 / 3</gadget>
<output>95</output>

<result>95</result>