Total Questions: 50
1 - 2 + 3 - 4 + 5 - 6 .... to 100 terms ⇒ (1 - 2) = -1, (3 - 4) = -1 and so no Total terms = 50 Therefore, 1 - 2 + 3 - 4 + 5 - 6 .... to 100 = 50 × - 1 = - 50
1+5+6+10+11+15+16+20+........