On the day of "Six and One" Children's Day, Dongdong bought two sets of books "Happy Planet" and "The Legend of the Seven Heroes of Rainbow Cat and Blue Rabbit" for a total of 144 yuan. The price of the "Happy Planet" series is that of "The Legend of the Rainbow Cat, Blue Rabbit and Seven Heroes" (5/7). How much is the price of "Happy Planet" series?
"六、一"儿童节那天，冬冬买了《快乐星球》和《虹猫蓝兔七侠传》两套丛书共用去144元．《快乐星球》丛书的价钱是《虹猫蓝兔七侠传》的(5/7)．《快乐星球》丛书的价钱是多少元？
<gadget id="calculator">5 / 7</gadget>
<output>5/7 = around 0.714286</output>

<gadget id="calculator">1 + (5/7)</gadget>
<output>12/7 = around 1.714286</output>

<gadget id="calculator">144 / (12/7)</gadget>
<output>84</output>

<gadget id="calculator">144 - 84</gadget>
<output>60</output>

<result>60</result>