To find the nth term of the series 2,6,18,54,162, we first determine if it is an arithmetic or geometric series.
Step 1: Find the common ratio.
Divide each term by its preceding term:
26=3
618=3
1854=3
54162=3
Since the ratio between consecutive terms is constant, this is a geometric series with a common ratio r=3.
Step 2: Identify the first term.
The first term of the series is a=2.
Step 3: Use the formula for the nth term of a geometric series.
The formula for the nth term (Tn) of a geometric series is:
Tn=a⋅rn−1
Step 4: Substitute the values of a and r into the formula.
Tn=2⋅3n−1
Step 5: Compare with the given options.
The derived nth term matches option A.
The final answer is A.