A bag contains 5 red balls and some blue balls. If the probability of drawing a blue ball is double that of red ball, find the number of blue balls in the bag.

For the following frequency distribution, draw an ogive and then use it to estimate the median.

For the same distribution, as given above, draw a histogram and then use it to estimate the mode.

In a single throw of two dice, what is the probability of getting

(i) a total of 9

(ii) two aces (ones)

(iii) at least one ace

(iv) a doublet

(v) five on one die and six on the other

(vi) a multiple of 2 on one and a multiple of 3 on the other ?