Find the Average #sscmaths

In a class 15 boys and 20 girls average marks is 42.15 boys average marks are 41.5. Find the average marks of girls?

The total sales of 100 outlets of a shopping complex is Rs. 45,000. The average sales of 30 of them is Rs.350. The average sale of another 20 of them is Rs. 860. Find the average sale of the remaining outlets (In rupees)

Find the average mark from the following :

Average cost of 10 pens is Rs.200 and average cost of 10 pencil is Rs.100. Find the average cost of all pens and pencils.

Average of 10 observation in a series is 64. If average of first 5 observation is 45 and last 3 observation is 71. Find the average of remaining.

Find the average of the first 97 natural numbers.