The factory shipped a batch of coal and used 75.45 tons, which was 7.7 tons less than the rest. How many tons of coal did the factory have in total?
工厂运来一批煤，用去75.45吨，用去的比剩下的少7.7吨，工厂原来共有多少吨煤？
<gadget id="calculator">75.45 + 7.7 + 75.45</gadget>
<output>158.6</output>

<result>158.6</result>