Question

find the sum of 20 term of the AP 1 4 7 10​

Answer 1

Your answer is sum of 20 terms of ap is 140

Answer 2

Answer:

560

Step-by-step explanation:

a = 1

d = 4-1=3

n = 20

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

Sn =20/2{2*1 + (20-1)3}

Sn =10 {2 + 19*3}

Sn =10 {2 + 54}

Sn =10 * 56

Sn =560