Of the cars sold during the month of July, 90 had air conditioning, 100 had automatic transmissions, and 75 had power steering. Five cars had all three of these extras. Twenty cars had none of these extras. Twenty cars had only air conditioning; 60 cars had only automatic transmissions; and 30 cars had only power steering. Ten cars had both automatic transmission and power steering. Required a). How many cars had both power steering and air conditioning? b). How many cars had neither power steering nor automatic transmission? c). How many had automatic transmission or air conditioning or both? d). How many cars were sold in July?