Practice Questions

Q87.If the vectors AB→ = 3ˆi + 4ˆk and AC→ = 5ˆi −2ˆj + 4ˆk are the sides of a triangle ABC, then the length of the median through A is: (1) √33 (2) √45 (3) √18 (4) √72

Q90.A number n is randomly selected from the set {1, 2, 3, … . , 1000} . The probability that is an integer is ∑ni=1 i (1) 0.331 (2) 0.333 (3) 0.334 (4) 0.332 JEE Main 2012 (12 May Online) JEE Main Previous Year Paper

Q75. a a + 1 a −1 a + 1 b + 1 c −1 Let a, b, c be such that b(a + c) ≠0. If −b b + 1 b −1 + a −1 b −1 c + 1 = 0, then the c c −1 c + 1 (−1)n+2a (−1)n+1b (−1)nc value of ' n ' is (1) zero (2) any even integer (3) any odd integer (4) any integer JEE Main 2009 JEE Main Previous Year Paper