Will its 12.75 because you add 3+9 =12 and you just put the 75 that's it
Total distance = 200 miles
Time needed for the first 100 miles
= 100 ÷ 40 = 2.5 hours
Time needed for the second 100 miles
= 100 ÷ 50 = 2 hours
Total time = 2.5 + 2 = 4.5 hours
Average speed = 200 ÷ 4.5 hours = 44.4 miles per hour