On Monday Bob used of a tank of gas to go on a college visit. On Tuesday he used of a1 1 2 5 8 tank to commute to work. On Thursday, he went to the doctor and used of a tank less than 1 3 he used on Tuesday. On Saturday, he took his friends on a hiking trip and used of the 3 4 amount he used on his college visits. How much gas did Bob use overall last week?