According to statistics, 5% of mineral water is generally wasted when drinking mineral water during meetings. If the annual consumption of mineral water for meetings in the whole country is 5 billion bottles, how many billion bottles of mineral water will be wasted in the whole country in a year?
据统计，会议时喝矿泉水，一般会浪费5%，如果全国每年会议矿泉水用量为50亿瓶，那么全国一年大约要浪费多少亿瓶矿泉水？
<gadget id="calculator">5 / 100</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">50 * (1/20)</gadget>
<output>5/2 = around 2.5</output>

<result>5/2 = around 2.5</result>