Agallon of gasoline cost 30 in 1960 and $1.30 in 1980. what was the percent increase in the price of gasoline?

I think the answer is 77 percent 
1.30*.77 is 1.001 plus .30 is 1.301 
its one cent over but if you do 76 percent it comes out to 1.288 so thats why i would say its 77 percent increase hope this helps