Samantha, Danielle, Jeff, and Isaac share minutes on their cell phone plan. Samantha used 1/4 of the minutes, Danielle used 0.5 of the minutes, and jeff used 0.2 of the minutes. what percent of the cell phone plan minutes are left for Issac to use? please help asap

Three friends went on a road trip from phoenix, az, to san diego, ca. mark drove 50 percent of the distance. jason drove 1/8 of the distance. andy drove the remainder of the distance. 1. andy thinks he drove 1/4 of the distance from phoenix, az, to san diego, ca. is andy correct? 2. the distance from phoenix, az, to san diego, ca, is 360 miles. how many miles did each person drive? 3. solve the problem. what is the answer in total?