The total of the pupils are the 100%, or in fraction mode, 1, the whole, so we have:
bus + car + foot = total
1/3 + car + 3/10 = 1
car = 1 - 3/10 - 1/3
car = 1 - (9/30 + 10/30)
car = 30/30 - 19/30
car = 11/30
that is the fraction that come by car
Okay, this is C. This is because since he has already driven 3.5miles so far, we already have that and we add it cause we have already driven that. Then, it says 100 miles for every TWO hours. For x, we need to find how many miles we drive in ONE hour. So: 100/2 miles = 2/2 hours: 50 miles = 1 hr.
Taking 20 away from 50 will result in 30
