49 expedition members crossed a small river, but there was only one rubber boat that could carry 7 people, and it took 3 minutes to cross the river once. How many minutes does it take for all the team members to cross the river to the other side?
49名探险队员过一条小河，只有一条可乘7人的橡皮艇，过一次河需3分钟．全体队员渡到河对岸最少需要多少分钟．
<gadget id="calculator">7 * 2</gadget>
<output>14</output>

<gadget id="calculator">14 + 1</gadget>
<output>15</output>

<gadget id="calculator">15 * 3</gadget>
<output>45</output>

<result>45</result>