Option (b) is correct

The series is in A.P with first term 12 and common difference 1.5

As we know,

T_n = a + (n – 1)d

T₅₁ = 12 + (51 – 1) x 1.5

T₅₁ = 12 + 50 x 1.5

T₅₁ = 12 + 75

T₅₁ =87

विकल्प (b) सही है

श्रृंखला A.P. (Arithmetic progression) में है जिसमें पहला पद 12 और सामान्य अंतर 1.5 है

जैसा कि हम जानते हैं,

T_n = a + (n – 1)d

T₅₁ = 12 + (51 – 1) x 1.5

T₅₁ = 12 + 50 x 1.5

T₅₁ = 12 + 75

T₅₁ =87