Core Mathematics

1The mean of x and y is 8 and the mean of x, y and z is 10. Find z.

2The standard deviation of a set of data measures

3In how many ways can 2 prefects be chosen from 5 candidates?

4A bag holds 4 red and 6 blue balls. Two are drawn without replacement. What is the probability that both are red?

5The marks of 5 students have mean 60. Four of the marks are 50, 55, 65 and 70. The fifth mark is

6From a group of 5 boys and 3 girls, 2 are chosen at random. P(one boy and one girl) is

7On a cumulative frequency curve, the median is read off at

8The probability that a student is late on any day is 0.1. Find the probability that he is late on exactly one of two days.

9Two cards are drawn without replacement from 3 red and 2 blue cards. P(both red) is

10In how many ways can 4 different books be arranged on a shelf?