Hudson's car was averaging 25 miles per gallon of gasoline. After switching fuels, his car now averages 29 mile per gallon.
What was the percent increase in fuel efficiency?

For the rule of 78, for a 12-month period, the last term in the sequence is 12 and the series sums to 78. for an 10 month period, the last term is and the series sum is . for a 15 month period, the last term is and the series sum is . for a 20 month period, the last term is and the series sum is