10:2/1/2+3×(5/2/3-5/2/3)

First, solve the division and multiplication in the parentheses:

5/2 = 2.5
2/3 = 0.6667

2.5 - 0.6667 = 1.8333

Now, substitute back into the equation:

10 ÷ 2 = 5
5 ÷ 1 = 5
5 + 3 × 1.8333
5 + 5.5 = 10.5

Therefore, the answer is 10.5.