Question

Which term of Ap 3,15,27,39....Will be 120 more than it's 21st term

Answer 1

Step-by-step explanation:

hope it helps!!

ppposjsbeyysbwbabhxbsjdnevd

Answer 2

Given sequence is 3, 15, 27, 39,...

The first term is a = 3

The common difference is d = 15-3

ㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤ= 12

We know that the nth term of the arithmetic progression is given by a +(n-1)d

Let the mth term be 120 more than the 21st term.

Therefore, 120+mth term = 21st term

$= > \: 120 + a + (m - 1)d = a + (21 - 1)d$

$= > \: 120 + (m - 1)12 = 20 \times 12$

$= > \: 12m - 12 = 240 + 120$

$= > \: 12m = 360 + 20$

$= > \: 12m = 372$

$= > \: m = \frac{372}{12}$

$= > \: m = 31$

Therefore, the 31st term is 120 more than the 21st term.