She has run 21 miles already. Let t be the number of additional miles added on.
In total, she has run t+21 miles
This is going to be set greater than 38 since "Ann will run more than 38 miles"
So we have this inequality
t+21 > 38
we solve for t by subtracting 21 from both sides
t+21 > 38
t+21-21 > 38-21
t+0 > 17
t > 17
The final answer is t > 17
which means that the possible additional number of miles she could run is anything larger than 17. So t = 18 is one possibility.
Answer is B(0,24) . I try my best to help you . Hope can help you.
Let's say 'x' to number of the students in the smaller class. Since the larger one is 6 more than the smaller one, its number would be 'x+6'. So their sum is equal to

and we know total is 50 so:
x is 22 so the larger number 'x+6' is equal to :
The sum of their speeds is (27/3) = 9 km/h.
One of them goes at 3 kmh and the other goes at 6kmh