Class 4 and Class 1 collected 20.5 kg of waste newspapers, and Class 4 and Class 2 collected 5.8 kg less than Class 4 and Class 1. How many kilograms of waste newspapers did the two classes collect in total?
四1班收集废报纸20.5千克，四2班比四1班少收集5.8千克．两个班一共收集废报纸多少千克？
<gadget id="calculator">20.5 - 5.8</gadget>
<output>14.7</output>

<gadget id="calculator">20.5 + 14.7</gadget>
<output>35.2</output>

<result>35.2</result>