If 19^ th terms of non -zero A.P. is zero, then its (49^ th term)… - Vidyadip

MCQ

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

A
$4 : 1$
B
$1 : 3$
✓
$3 : 1$
D
$2 : 1$

✓

Answer

Correct option: C.

$3 : 1$

c
$a + 18d = 0 \Rightarrow a = - 18d$

$\frac{{{t_{49}}}}{{{t_{29}}}} = \frac{{a + 48d}}{{a + 28d}} = \frac{{ - 18d + 48d}}{{ - 18d + 28d}}$

$ = \frac{{30d}}{{10d}} = 3$

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