Question

If the nth term of an AP is 24, 20 ,16 ,12 etc is same as the nth term of AP
is -11,-8,-5,-2 etc find n

Answer 1

Step-by-step explanation:

Here is your answer

hope it helps you

Answer 2

1. First progression

a=24

d=20-24=16-20=(-4)

$an = a + (n - 1)d$

$an = 24 + (n - 1) \times - 4$

$an = 24 + 4 - 4n$

$an = 28 - 4n.....(i)$

2. Second Progression

a=-11

d=-8-(-11)=-5-(-8)=3

$an = a + (n - 1)d$

$an = - 11 + (n - 1) \times 3$

$an = - 11 + 3n - 3$

$an = - 14 - 3n......(ii)$

NOW,

Equating (i) and (ii)

$28 - 4n = - 14 - 3n$

$28 + 1 4= - 3n + 4n$

$n = 42$

Hence there are 42 terms