What is the rightmost digit preceding the zeros in the value of 30^30?

1. The question asks for the rightmost digit *before* the zeros in $30^{30}$.\n2. We know from previous analyses of trailing zeros [1], [71] that zeros at the end of a number come from factors of 10. So, we can split the number: $30^{30} = (3 \\times 10)^{30} = 3^{30} \times 10^{30}$.\n3. The term $10^{30}$ just adds 30 zeros to the end. The digit immediately before these zeros is simply the unit digit of $3^{30}$.\n4. Now, we use the 'Cyclicity of Base 3' concept, which is a frequent PYQ theme [13], [16], [81]. The powers of 3 end in a repeating pattern: 3, 9, 7, 1. The cycle length is 4.\n5. To find where $3^{30}$ lands in this cycle, we divide the exponent 30 by the cycle length 4.\n6. $30 \\div 4 = 7$ with a remainder of 2. (This 'Modulo' approach is standard for pattern finding [84]).\n7. A remainder of 2 means the unit digit is the 2nd number in the cycle ($3^2$).\n8. $3^2 = 9$. Therefore, the digit is 9.