The mean of the five observations x, x + 2, x + 4, x + 6, x + 8 is 11. Then, the mean of the first three observations is

• 12

• 2

• 20

• 9

A bag has 5 red marbles, 4 green marbles and 3 blue marbles. All marbles are identical in all respects other than colour. A marble is taken out from the bag without looking into it. What is the probability that it is a non-green marble?

• $\frac{1}{3}$

• $\frac{2}{3}$

• $\frac{7}{12}$

• $\frac{5}{12}$

Histogram is used to represent

• non-continuous grouped frequency distribution

• ungrouped frequency distribution

• continuous grouped frequency distribution

• All of the above

A bag contains 4 black balls, 6 blue balls, 3 white balls and 5 red balls. One ball is drawn from the bag. Probability that the ball drawn is black or white

• $\frac{5}{18}$

• $\frac{7}{18}$

• $\frac{4}{15}$

• $\frac{4}{5}$

Mode of the given data 25, 23, 22, 21, 24, 23, 25, 23, 22, 21, 23, 24, 23, 22, 23 is

• 23

• 22

• 21

• 24