The number of terms in the series 1 + 3 + 5 + 7 ...+ 73

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The number of terms in the series 1 + 3 + 5 + 7 ...+ 73 + 75 is

1. 28
2. 30
3. 36
4. 38

Correct Option: D

Let the number of terms be n.
It is an Arithmetic Series whose first term, a = 1 and common difference d = 2.
∴ n^th term = a + (n - 1)d
⇒ 75 = 1 + (n - 1)2
⇒ 2(n - 1)= 74

⇒ n - 1 =	74	= 37
	2

⇒ n - 1 = 37 ⇒ n = 37 + 1 = 38