taborella8 taborella8 31-05-2018 Mathematics contestada Caleb practices piano 20 minutes per day, and he practices guitar 30 minutes per day. Which expression represents the number of minutes Caleb spends practicing instruments after d days? Select each correct answer. A. 20+d+30+d B. d(20+30) C. 20(30+d) D. 20d+30d