Please solve this question N is a number such that 100≤N≤1000. If the middle digit of the number N is average of other 2 digits and the ratio of first 2 digit to the last 2 digit is equal to the ratio of sum of first 2 digit to the sum of last 2 digit. How many values of N are possible?

Please solve this question N is a number such that 100≤N≤1000. If the middle digit of the number N is average of other 2 digits and the ratio of first 2 digit to the last 2 digit is equal to the ratio of sum of first 2 digit to the sum of last 2 digit. How many values of N are possible?