Answer:
B
Step-by-step explanation:
This is proportional because the number of calories burned is directly proportional to the amount of time spent on the treadmill
6/3 = 2
10^4/10^-5 = 10^9
so it's 2 x 10^9
answer
<span>A 2 × 10^9</span>
This is a VERY long question XD