Question:
What is the 30th term of the series? 7, 11, 15, 19, …
शृंखला का 30वाँ पद क्या है? 7, 11, 15, 19, …
Options:
- 123
- 127
- 131
- 135
- 123
- 127
- 131
- 135
Correct Answer: a)
Explanation:
This is an arithmetic progression with first term \(a = 7\) and common difference \(d = 4\).
\(T_n = a + (n – 1)d \implies T_{30} = 7 + (30 – 1) \times 4 = 7 + 29 \times 4 = 7 + 116 = 123\).
समानांतर श्रेणी: \(a = 7\), \(d = 4\)।
\(T_{30} = 7 + (30 – 1) \times 4 = 7 + 116 = 123\)।