Question

the first term and the common difference of an A.P is 10000 and 2000 respectively find the sum of first 12 terms of the AP

Answer 1

Answer:

132144

Step-by-step explanation:

sn=n/2 (2n+(n-1)*d)

substitute values

Answer 2

Answer:

252000

Step-by-step explanation:

Let Sn be the sum of the first n terms of an Arithmetic progression.

The formula do the sum is given by :

Sn = n/2[2a + (n - 1)d]

Where :

n = The number of terms

a = the first term.

d = the common difference.

In our case :

n = 12

d = 2000

a = 10000

Doing the substitution we have :

S12 = 12/2[2 × 10000 + (12 - 1)2000]

Performing the operation we have :

= 6(42000)= 252000

Therefore the sum of the first 12 terms of the AP is given as :

252000