Problems on Numbers - General Questions

The sum of two numbers is 23 and their product is 112. What is the sum of their squares?

The sum of two numbers is 48 and their difference is 14. What is the larger number?

The difference between a two-digit number and the number obtained by interchanging its digits is 45. What is the difference between the two digits?

The sum of two numbers is 36 and their difference is 16. What is the larger number?

A number exceeds its one-fifth by 48. What is the number?