A bottle of oil weighs 2.7 kilograms. After half of the oil is poured out, the weight of the bottle is 1.45 kilograms. How many kilograms of oil are there in the bottle?
一瓶油连瓶重2.7千克，倒出一半油后，连瓶重1.45千克，瓶里原有多少千克油．
<gadget id="calculator">2.7 - 1.45</gadget>
<output>1.25</output>

<gadget id="calculator">1.25 * 2</gadget>
<output>2.5</output>

<result>2.5</result>