(i) Consider the cases where the first and last cans are the same type:

• If they are cola, the arrangement is \\frac{5!}{2!2!} = 30\ ways.
• If they are green tea, the arrangement is \\frac{5!}{3!2!} = 10\ ways.
• If they are orange juice, the arrangement is \\frac{5!}{3!2!} = 10\ ways.

\(Total arrangements = 30 + 10 + 10 = 50\ ways.\)

\((ii) Treat the 3 cans of cola as a single block. The arrangement without restriction is \\frac{5!}{2!2!} = 30\ ways.\)

\(Now consider the case where both colas and green teas are together: \\frac{4!}{2!} = 12\ ways.\)

\(Subtract the restricted case from the total: 30 - 12 = 18\ ways.\)