There are 15 rows of students doing morning exercises on the playground, and the number of each row is equal. Wang Yuan is standing in the fifth row. Counting from the beginning, she is the fifth, and counting from the end, she is the seventh. How many students are there in the playground?
操场上有15排同学做早操，每排人数相等．王苑站在第五排，从排头开始数，她是第5个，从排尾数起，她是第7个，操场上一共有多少个同学．
<gadget id="calculator">7 - 1</gadget>
<output>6</output>

<gadget id="calculator">5 + 6</gadget>
<output>11</output>

<gadget id="calculator">11 * 15</gadget>
<output>165</output>

<result>165</result>