Best rentals charges a daily fee plus a mileage fee for renting its cars. barney was charged $81 for 3 days and 300 miles, while mary was charged $145 for 5 days and 600 miles. what does best rental charge per day and per mile?

Lindsie is painting on a canvas with dimensions of 3 ft by 4 ft. she wants to make a display model for a gallery that has twice the area of the original. how much should she increase the length and width by, if she wants to increase them by the same amount? round your answer to the nearest tenth.