i need help with my math homework

Question

the average of five numbers is 18. let the first number be increased by 1, the second number by 2, the third number by 3, the fourth number by 4,and the fifth number by 5. what is the average of set of increased numbers?

Answer 1

The formula for the average of 5 numbers is:

(sum of the five numbers)/5 = average = 18

sum of the five numbers = 18·5 = 90

sum of the five numbers + 1 + 2 + 3 + 4 + 5 = 90 + 15 = 105

105/5 = the new average = ____?