Rita drove a total of 120 miles at 40 miles per hour. tom drove a total of 100 miles at 50 miles per hour. which explanation correctly describes a way to calculate the total number of hours rita and tom drove? a. step 1 divide: 120 ÷ 40 step 2 divide: 100 ÷ 50 step 3 add the two quotients. b. step 1 divide: 120 ÷ 40 step 2 divide: 100 ÷ 50 step 3 subtract the two quotients. c. step 1 add 120 + 40. step 2 add 100 + 50 step 3 divide the two sums by 2. d. step 1 subtract 120 – 40. step 2 subtract: 100 – 50. step 3 divide the two differences by 2.