3 1/3×(10 4/5×5 5/12+10 4/5) = 231
1) 10 4/5×5 5/12 = 54/50×65/60 = 58 1/2
2) 58 1/2 + 10 4/5 = 69 3/10
3) 3 1/3 × 69 3/10 = 231
