Age (in years) of 6 children of two groups are recorded as below:

(a) Find the mode and range for each group.
(b) Find the range and mode if the two groups are combined together

The ages of 40 students of a group are given below : Find their mean

The average age of group of 20 girls is 15 yr and that of another group of 25 boys is 24 yr. The average ageof the two groups mixed together is

Find the mode of following destribution by Grouping

How many children are there in the group ? (i) Average age of the children in this group is 15 years. The total ages of all the children in this group is 240 years. (ii) The total age of all the children in the group and the teacher is 264 years. The age of the teacher is 9 years more than average age of the children.

Average age of a group of 30 boys is 16 years. A boy of age 19 leaves the group and a new boy joins the group. If the new average age of the group is 15.8 years, find the age of the new boy.

If the combined mean of two groups is (40)/(3) and if the mean of one group with 10 observations is 15 then the mean of the other group with 8 observations is equal to

Two-thirds of children are in the age group 1-12 yr. Of this, if three-fourths are in the age group of 1-8 yr. Find the fraction of children in the age group of 9-12 yr?