Question:
The circumference of Earth is 40,000 kilometers. How many trips around Earth could you take if you travel one billion meters?

Answer:
First, convert one billion meters to kilometers.

\[1000000000 \textnormal{ meters} \cdot \frac{1 \textnormal{ kilometer}}{1000 \textnormal { meters}} = 1000000 \textnormal{ kilometers}\]

Next, we divide the total distance traveled by the circumference around the Earth to get the total number of trips around the world, or $\frac{1000000}{40000} = \boxed{25}$ trips.