The average of the three numbers A, B, and C is 25. It is known that the sum of the two numbers B and C is 60. What is the number of A?
甲、乙、丙三个数的平均数为25，已知乙、丙两个数的和是60，甲数是多少
<gadget id="calculator">25 * 3</gadget>
<output>75</output>

<gadget id="calculator">75 - 60</gadget>
<output>15</output>

<result>15</result>