1) Find the average height of five students with heights 142,147,153,165,157 in cms?
Answer is 152.8
2) The average marks of girls in a class is 62.5. The average marksof 4 girls among them is 60.The average marks of remaining girls is 63,then what is the number of girls in the class?
Answer is 10
3) The average price of 10 books is increased by 17 Rupees when one of them whose value is Rs.400 is replaced by a new book.What is the price of new book?
Answer is 570
4) The average age of Mr and Mrs Sharma 4 years ago is 28 years .If the present average age of Mr and Mrs Sharma and their son is 22 years. What is the age of their son?
Answer is 2