"Basic" 11 (corrected)

Relevant wiki: Number Base - Converting to Different Bases

We know that :

$11 = 8 + 2 + 1 = 2^3 + 2^1 + 2^0 \Rightarrow a = 1011$

$11 = 3^2 + 2 \times 3^0 \Rightarrow b = 102$

$11 = 2 \times 4^1 + 3 \times 4^0 \Rightarrow c = 23$

$11 = 2 \times 5^1 + 5^0 \Rightarrow d = 21$

$11 = 6^1 + 5 \times 6^0 \Rightarrow e = 15$

$11 = 7^1 + 4 \times 7^0 \Rightarrow f = 14$

$11 = 8^1 + 3 \times 8^0 \Rightarrow g = 13$

$11 = 9^1 + 2 \times 9^0 \Rightarrow h = 12$

$11 = 11^1 \Rightarrow j = 10$

$\Rightarrow \frac{1}{11}(a+b+c+d+e+f+g+h)=\frac{1011+102+23+21+15+14+13+12+10+11}{11} = \frac{1232}{11} = 112$