Two numbers are chosen at random from{1, 2, 3, 4, 5, 6, 7, 8} at a time. The probability that smaller of the two numbers is less than 4 is
Two fair dice are rolled. The probability of the sum of digits on their faces to be greater than or equal to 10 is
A bag contains 2n + 1 corns. It is known that n of these coins have a head on both sides, whereas the remaining n + 1 coins are fair. A coin is picked up at random from the bag and tossed. If the probability that the toss results in a head is , then n is equal to
10
11
12
13
The random variable takes the values 1, 2, 3, 1 ..., m. If P(X = n) = to each n, then the variance of X is
The direction ratios of the two lines AB and AC are 1, - 1, - 1 and 2, - 1, 1. The direction ratios of the normal to the plane ABC are
2, 3, -1
2, 2, 1
3, 2, - 1
- 1, 2, 3
A plane passing through(- 1, 2, 3) and whose normal makes equal angles with the coordinate axes is
x + y + z + 4 = 0
x - y + z + 4 = 0
x + y + z - 4 = 0
x + y + z = 0
C.
x + y + z - 4 = 0
A variable plane passes through a fixed point (1, 2, 3). Then, the foot of the perpendicular from the origin to the plane lies on
a circle
a sphere
an ellipse
a parabola