Xiaoyue and Dongdong go to the supermarket to buy fruit. Xiaoyue bought 2 kilograms of oranges, 3 kilograms of apples and 4 kilograms of pears for a total of 28.5 yuan. Dongdong bought 3 kilograms of oranges, 5 kilograms of apples and 7 kilograms of pears for a total of 47.7 yuan. I ran into a teacher at the checkout, and the teacher bought 6 kilograms of oranges and 3 kilograms of apples, so how much should the teacher have spent?
小悦、冬冬去超市买水果．小悦买了2千克桔子、3千克苹果和4千克梨，共花了28.5元，冬冬买了3千克桔子、5千克苹果和7千克梨，共花了47.7元．结账的时候碰到老师，老师买了6千克桔子和3千克苹果，那么老师应该花了多少钱？
<gadget id="calculator">28.5 * 7</gadget>
<output>199.5</output>

<gadget id="calculator">47.7 * 4</gadget>
<output>190.8</output>

<gadget id="calculator">199.5 - 190.8</gadget>
<output>8.7</output>

<gadget id="calculator">6 / 2</gadget>
<output>3</output>

<gadget id="calculator">8.7 * 3</gadget>
<output>26.1</output>

<result>26.1</result>