If 19 th term of a non-zero A.P. is zero,

Question:

If 19 th term of a non-zero A.P. is zero, then its $(49$ th term $)$ :(29th term) is :-

1. $3: 1$

2. $4: 1$

3. $2: 1$

4. $1: 3$

Correct Option: 1

Solution:

$a+18 d=0$         ......(1)

$\frac{a+48 d}{a+28 d}=\frac{-18 d+48 d}{-18 d+28 d}=\frac{3}{1}$