P5_A You can replace them with the single if statement: if (n >= 2) n = (n >=7 ? n-7 : 3*n+1); P5_B i. They're not playing each other. ii. One's a nickel, the other's a quarter (and yes, one is not a nickel). P5_C When a reference to an array is made, the index must be >= 0 and < the size of the array. Java always checks to see if the index in a reference to a particular array lies in the valid range of indexes for that array. If the index is invalid, Java throws an exception called ArrayIndexOutOfBoundsException to alert the programmer.