If A, B and C are mutually exclusive and exhaustive events of a random experiment such that P(B) = P(A) and P(C) = P(B), then P(A ∪ C) equals to
The mean of four observations is 3. If the sum of the squares of these observations is 48, then their standard deviation is
C.
If there is an error of ± 0.04cm in the measurement of the diameter of a sphere, then the approximate percentage error in its volume, when the radius is 10cm, is