The sum of the two numbers A and B is 30.58. Move the decimal point to the right for number A. At this time, the ratio of A and B is 1:1. What is the original number A?
甲、乙两数的和是30.58，甲数把小数点向右移动一位，这时，甲、乙两数的比是1：1，甲数原来是多少．
<gadget id="calculator">10 + 1</gadget>
<output>11</output>

<gadget id="calculator">30.58 / 11</gadget>
<output>2.78</output>

<result>2.78</result>