Xiao Ming is a third-year junior high school student. His age this year is exactly a multiple of 5. His mother’s age is three times that of Xiao Ming’s. How old is his mother this year?
小明是一名初三学生，他今年的年龄正好是5的倍数，妈妈的年龄是小明的3倍，妈妈今年多少岁？
<gadget id="calculator">15 * 3</gadget>
<output>45</output>

<result>45</result>