Question

In an ap a = 3 , n = 8 ,S =192 find d

Answer 1

hai!!

We know that formula Sn=n/2[ 2a+(n-1) d]

so,

given that a = 3 , n = 8 , s = 192

=> 192 = 8/2[6+(8-1)d]


=> 192= 4[6+7d-d]

=> 192/4=6+7d

=> 48 - 6 = 7d

=> 42/7= d

=> d = 6


hope it's help you

Answer 2

$Hii$‼

First term, a = 3
Number of terms, n = 8
Sum of terms, S = 192


As we know,
$S^n= \frac{n}{2}[2a+(n-1)d]$

We have to find the common difference i.e., d


Now, substituting the values of a, n and S in the above formula :-

$192 = \frac{8}{2}[2(3)+(8-1)d]$

$192=4(6+7d)$

$\frac{192}{4}=6+7d$

$48=6+7d$

$7d=48-6$

$7d=42$

$d=\frac{42}{7}$

$d=6$


Hence, the common difference is 6 .