The grades of 36 students in a test are shown in the pie chart above. How many students had excellent?

The table above shows that the scores of a group of students in a test. If the average score is 3.5, find the value of x

The model height and range of heights 1.35, 1.25, 1.35, 1.40, 1.35, 1.50, 1.35, 1.50, and 1.20 are m and r respectively. Find m+2r.

Find the value of t if the standard deviation of 2t, 3t, 4t, 5t, and 6t is √2

In how many ways can 6coloured chalks be arranged if 2 are same colour?