Question

50^th term of the sequence 3 + 12 + 25 + 42 + ……. Is

• A. 5145
• B. 5148
• C. 5142
• D. 5195

Answer 1

Answer: (B)

5148

Answer 2

S = 3 + 12 + 25 + 42 .... + T_n ...(1)

S = 3 + 12 + 25 ..................... + T_n ...(2)

subtract

0 = 3 + 9 + 13 + 17 .....T_n

T_n = 3 + $\frac{(n - 1)}{2}$ [18 + (n – 2)4]

Put n = 50 \ T₅₀ = 5148