How do I do these questions without hardcoding and using inbuilt libraries

/** * * @param n * @param low * @param high (assume low is less than or equal to high) * @return true if n is in the range [low...high], false otherwise */ public boolean isInRange(int n, int low, int high) { return false; }

/** * * @param n (assume n is more than 0) * @return the sum of the first n positive EVEN integers (2+4+...+(2*n)) */ public int sumEvenV1(int n) { return n; } /** * * @param n (assume n is more than 0) * @return the sum of the first n positive ODD integers (1+3+...+(2*n-1)) */ public int sumOddV1(int n) { return 0; }