Question

find the sum of arithmetic progression 2,5,8,11 to 12 terms​

Answer 1

Answer:

222

Step-by-step explanation:

a=2,d=5-2 = 3 , n = 12 ,Sn =?

Sn = n/2 { 2a + (n-1) d}

Sn = 12/2{2(2) + (12-1)3}

Sn = 12/2 { 4 +11(3)}

Sn = 12/2{4+33}

Sn = 12/2 {37}

Sn = 6 {37}

Sn = 222