How far could you drive on 50 gallons of gas

Aregression was run to determine if there is a relationship between hours of tv watched per day (x) and number of situps a person can do (y). the results of the regression were: y=ax+b a=-0.662 b=30.418 r2=0.703921 r=-0.839

On saturday a souvenir shop had 125 customers.sixty four percent of the costumers paid with a credit card. how many costumers paid with cash?

Someone me! if you’re smart you can solve this!