For one bolt in the outer circle:
$P_1 = A\tau = \dfrac{\pi (10^2)}{4}(60)$
$P_1 = 1500\pi \, \text{N}$
For one bolt in the inner circle:
$\dfrac{P_1}{R_1} = \dfrac{P_2}{R_2}$
$\dfrac{1500\pi}{200} = \dfrac{P_2}{150}$
$P_2 = 1125\pi \, \text{N}$
$T = P_1 R_1 n_1 + P_2 R_2 n_2$
$T = 1500\pi(200)(8) + 1125\pi(150)(6)$
$T = 3\,412,500\pi \, \text{N}\cdot\text{mm}$
$T = 3.4125\pi \, \text{kN}\cdot\text{m} = 10.72 \, \text{kN}\cdot\text{m}$ answer