Visitors to a cinema are either children, adults or pensioners. The ratio of children to adults is 2:5. The ratio of adults to pensioners is 3:4. A stratified sample of 315 is to be taken from the visitors. How many pensioners should be in the sample?

Add the two expressions 3.8b - 7 and 2.9b + 9 enter your answer in simplified form

The random variable x is the number of occurrences of an event over an interval of ten minutes. it can be assumed that the probability of an occurrence is the same in any two-time periods of an equal length. it is known that the mean number of occurrences in ten minutes is 5.3. the appropriate probability distribution for the random variable

Simplify (2^5/3^2)^4 a. 2^20/3^8 b. 2^9/3^8 c. 8^5/12^2 d. 2/3^2