Question

)S10 in an Arithmetic progression if the sum of first 3 terms is 9 and sum of next 3 terms is 27 is A) 30 B) 38 C) 46 D) 36​

Answer 1

Step-by-step explanation:

a + a + d + a + 2d = 9

3a + 2d = 9

a = (9 - 2d)/3 eq(i)

a + a + d + a + 2d + a + 3d + a + 4d + a + 5d = 27

6a + 15d = 27

a = (27 - 15d)/6 eq(ii)

a = a

(9 - 2d)/3 = (27 - 15d)/6 [ Dividing both sides by 3]

9 - 2d = (27 - 15d)/2

18 - 4d = 27 - 15d

11d = 9

d = 9/11

put the value of d in any if the equation

Note: Sum has formula Sum = n/2(2a + (n-1)d)

And

please check calculation once again

hope it helps!!