The four study groups A, B, C, and D have a total of 280 books. The head teacher suggested that the four groups have the same number of books, which was supported, so 14 books were transferred from A to B, 15 books were transferred from B to C, and 15 books were transferred from C to C. Transfer 17 books to D, and transfer 18 books from D to A. At this time, there are as many books in the four groups. This shows how many books Group A originally had.
甲、乙、丙、丁四个学习小组共有图书280本，班主任老师提议让四个组的书一样多，得到拥护，于是从甲调14本给乙，从乙调15本给丙，从丙调17本给丁，从丁调18本给甲．这时四个组的书一样多．这说明甲组原来有书多少本．
<gadget id="calculator">280 / 4</gadget>
<output>70</output>

<gadget id="calculator">70 - 18</gadget>
<output>52</output>

<gadget id="calculator">52 + 14</gadget>
<output>66</output>

<result>66</result>