The value of such that the system of equations 2x - y - 2z = 2; x - 2y + z = - 4; x + y + z = 4, has no solution, is
3
1
0
- 3
The variance of first 20 natural numbers is
133/4
279/12
133/2
399/4
A.
133/4
Variance of n natural numbers
If the letters of the word 'PROBABILITY' are written down at random in a row, then probability that two B's are together, is
A fair coin is tossed-at a fixed number of times. If the probability of getting exactly 3 heads equals the probability of getting exactly 5 heads, then the probability of getting exactly one head is
1/64
1/32
1/16
1/8