Use the sum of all her marks and then try to find the average.

Look for the number(s) which appears maximum number of time,

What is the most common age of the students?

Think of your 6 times table.

Remeber the method which we were doing to find the average.

How can we find the median of the data when number of entries are even?

Arrange the numbers in increasing order first and find the range with the help of maximum and minimum number.

Look for the number(s) which appears maximum number of time,

Try to look for the number which occured maximum number of times.

There should be equal no of hours in each day.