43 people want to cross a big river. There is only one rubber boat, which can accommodate up to 7 people (including one person at the helm) at a time. It is known that it takes 5 minutes to cross the river to the opposite bank in a rubber boat. how many minutes.
43人要过一条大河，只有一只橡皮艇，每次最多可坐7人(包括一人掌舵)，已知乘橡皮艇过河到对岸需要5分钟，假设来回的速度一样，他们全部过河需多少分钟．
<gadget id="calculator">43 - 1</gadget>
<output>42</output>

<gadget id="calculator">7 - 1</gadget>
<output>6</output>

<gadget id="calculator">42 / 6</gadget>
<output>7</output>

<gadget id="calculator">6 * 2 * 5</gadget>
<output>60</output>

<gadget id="calculator">60 + 5</gadget>
<output>65</output>

<result>65</result>