Question

Find the sum of first 20odd natural numbers​

Answer 1

Answer:

400

Step-by-step explanation:

$a = 1 \: .d = 2 \: .n = 20 \\ 20 \div 2(2(1) + (20 - 1)2) \\ 10(2 + (19)2) \\ 10(2 + 38) \\ 10(40) \\ 400$