Pour one glass of water into an empty bottle, and the total weight of the bottle is 140 grams. If three glasses of water are poured, the total weight of the bottle is 260 grams. What is the weight of the empty bottle in grams?
把一杯水倒入空瓶，连瓶共重140克，如果倒入三杯水，连瓶共重260克．空瓶的重量是多少克．
<gadget id="calculator">260 - 140</gadget>
<output>120</output>

<gadget id="calculator">120 / 2</gadget>
<output>60</output>

<gadget id="calculator">140 - 60</gadget>
<output>80</output>

<result>80</result>