During the "Six One" Children's Day, Xinhua Bookstore launched book discount sales activities. Wang Xiong bought a set of science and technology books with a 30% discount and paid 84 yuan. What was the original price of this set of books?
"六一"儿童节期间，新华书店推出图书打折销售活动．王雄买了一套打七折的科技书，付了84元，这套书的原价是多少？
<gadget id="calculator">70 / 100</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">84 / (7/10)</gadget>
<output>120</output>

<result>120</result>