Q1: The sum of first 45 natural numbers is:

ANS:A - 1035

Let S_n = (1 + 2 + 3 + ... + 45) This is an A.P. in which a = 1, d = 1, n = 45 and l = 45

Sn =	n	(a + l)	=	45	x (1 + 45)   = (45 x 23)   = 1035
	2			2

Required sum = 1035.