Pls answer and explain the situation of the problem to me

Mr. Arnold needs to paint 1,600 square feet of his house. Each gallon of paint will cover 250 square feet. So you would divide 1600 by 250 to figure out how many cans he needs. the answer is 6.4. Then it says that he had one left over from the last time he painted his house. So he only needs 5.4 gallons now. The end question is whether or not Mr. Arnold needs more than 5 gallons and the answer is yes. Because he needs 5.4 gallons. .4 gallons more than 5.

A) for the n row: 22+(n-1)×6therefore,b) 100-22=78that means (n-1)×6=7878÷6=1313+1=1414th row has 100 seats