Question

The boat covers 25 km each hour. If 1 nautical mile is about 2 km, how far into the ocean did they go?

Answer 1

Distance covered by boat in 1 hr = 25 km
Distance covered by boat in 4 hrs = 25 x 4 = 100 km

1 nautical mile = 2 km (approximately)
Therefore,
1 km = $\frac{1}{2}$ nautical miles (approximately).
100 km = 100 $\times \frac{1}{2}$ = 50 nautical miles (approximately).

Option b is the correct answer.