The `12^(th)` term and `15^(th)` term of an AP are 68 and 86 respectively. Find its `18^(th)` term

Explanation

To find the 18th term of the arithmetic progression (AP) where the 12th term is 68 and the 15th term is 86, we can follow these steps:

### Step 1: Set up the equations for the 12th and 15th terms.
The general formula for the nth term of an AP is given by:
\[ T_n = a + (n - 1) \cdot d \]
where:
- \( T_n \) is the nth term,
- \( a \) is the first term,
...