Question
An unbiased coin is tossed until a head appears. The
expected number of tosses required isSolution
Let X denote the number of tails tossed before the head appears. Then X is a geometric random variable. P(head) = 1 / 2 and the expectation is E(X)=1 / (1/2) = 2.
Pipe ‘A’ and pipe ‘B’ can fill a cistern in 20 minutes and 15 minutes respectively. Pipe ‘C’ alone can empty the cistern in 12 minutes. If a...
24, 29, 62, ?, 758, 3791
...Matthew sells Chocolates in the packs of 6 chocolates, 12 chocolates, 18 chocolates and 24 chocolates etc, but the rate is necessarily uniform. One day ...
If the standard deviation of a population is 5.5, what would be the population variance?
14, 28, 56, 112, ...... The sum of first 10 numbers in the series is:
The ratio of length and breadth of a rectangular field is 5:9. If the total cost of surrounding it at the rate of Rs 7.50 per meter is Rs 4200, then fin...
The fourth term of an arithmetic progression is 6. Then the sum of first seven terms is:
What is the median of the following list of numbers: 5, 3, 6, 9, 11, 19,12,20, and 1?
What is least number which when successively divided by 6, 4 and 4 leaves a remainder 5, 3 and 3 respectively?
Find the mode of the data: 2, 2, 3, 5, 15, 15, 15, 20, 21, 23, 25, 15, 23, 25.
