public static int mystery(int value)
{
    if(value <= 10)                             // checks if 15 <= 10, which is false
        return value * 3;
    
    return value + mystery(mystery(value / 5)); // computes 15 + something unknown
    //              call2     call 1               stops at call 1 and calls m(3)
}

Call stack

m(3)
m(15)1    15 + ____
m(5)   returns 15
m(27)2    27 + ____
m(9)   returns 27
m(45)2    45 + ____

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