15 tons of water are needed to produce 1 ton of oil. According to this calculation, how many tons of water are needed to produce 60 tons of oil.
生产1吨石油需用水15吨，照这样计算，生产60吨石油需要多少吨水．
<gadget id="calculator">60 * 15</gadget>
<output>900</output>

<result>900</result>