Xiao Lin's mother went to the market to buy fruit. She first bought 2.5kg of apples for 3.5 yuan, and is planning to buy 3kg of oranges. The unit price of oranges is 1.6 times that of apples. How much should she pay for oranges?
小林的妈妈去市场买水果．她先花3.5元买了2.5kg苹果，还准备买3kg橙子，橙子的单价是苹果的1.6倍，买橙子应付多少钱？
<gadget id="calculator">3.5 / 2.5</gadget>
<output>1.4</output>

<gadget id="calculator">1.4 * 1.6 * 3</gadget>
<output>6.72</output>

<result>6.72</result>