Its 20 oz when Hot as Venti means 20 in Italian. Although for cold beverages its 24 oz. Same is for Trenta cup, as Trenta means 30 in Italian. Trenta cup is reserved for cold beverages in Starbucks. Trenta cup = 30 oz cold beverage.
A utility bill would be a bill for your water, electric, gas, etc.
When considering average utility costs per month, electricity and gas are likely to make up the largest amount of your bills. You have to consider the size of your apartment and the general climate. An average electric bill may be as low as $30 per month or as high as $100.