The answer depends on the inner core of WHAT! And since you have not bothered to share that crucial bit of information, I cannot provide a more useful answer.
From the Wikipedia: "The outer core of the Earth is a fluid layer about 2,300 km ... thick" - With current technology, it isn't possible to go that deep AT ALL.If you just want a calculation based on a hypothetical machine, assume some speed, and then divide the distance by the speed.
The Earth's core is about 6,371 kilometers from the surface to its center. The outer core extends from about 2,890 km to 5,150 km below the Earth's surface, while the inner core extends from about 5,150 km to 6,371 km below the surface.
4 kilometers = 2.485 miles (rounded)
101 kilometers are 62.7 miles.
200 kilometers = 124.274238 miles
The thickness of the inner core is 1,200 km. 1,200 km being the radius of the sphere known as the inner core.
300,000 kilometers = 186,411 miles (rounded)
New York State is 330 miles (530 kilometers) long.
1,038 kilometers = 644.98 miles (rounded)
9,321 miles.
1225 miles.
4,163.187 miles.