The school newly purchased 280 books and distributed them to 3 classes according to the number of students. There are 45 students in the first class, 47 students in the second class, and 48 students in the third class. How many books are divided into the first class and the third class?
学校新购来280本书，按人数分配给3个班，一班有45人，二班有47人，三班有48人，一班和三班共分得多少本图书？
<gadget id="calculator">45 + 47 + 48</gadget>
<output>140</output>

<gadget id="calculator">45 / 140</gadget>
<output>9/28 = around 0.321429</output>

<gadget id="calculator">280 * (9/28)</gadget>
<output>90</output>

<gadget id="calculator">48 / 140</gadget>
<output>12/35 = around 0.342857</output>

<gadget id="calculator">280 * (12/35)</gadget>
<output>96</output>

<gadget id="calculator">90 + 96</gadget>
<output>186</output>

<result>186</result>