RRB Technician Grade I 13 March 2026 Paper

Concept:The $n$th term of an AP is given by $T_n = a + (n-1)d$.Use the given conditions to form equations and solve for the first term $a$ and the common difference $d$.Explanation:Let the first term be $a$ and the common difference be $d$.Given: $T_8 + T_{12} = 100$.Using $T_n = a + (n-1)d$, we write:$$(a + 7d) + (a + 11d) = 100$$$$2a + 18d = 100$$$$a + 9d = 50 \quad \text{...(1)}$$Also, the 20th term is 95, so:$$a + 19d = 95 \quad \text{...(2)}$$Subtract equation (1) from equation (2):$$(a + 19d) - (a + 9d) = 95 - 50$$$$10d = 45$$$$d = 4.5$$Substitute $d = 4.5$ into equation (1):$$a + 9(4.5) = 50$$$$a + 40.5 = 50$$$$a = 9.5$$Now calculate the 7th term:$$T_7 = a + 6d = 9.5 + 6(4.5)$$$$T_7 = 9.5 + 27 = 36.5$$Answer:The 7th term is $36.5$.Therefore, the correct option is D. 36.5.