Well, there's no jet that can travel at that speed ... 14.75 km/s is like 33,000 miles per hour ! But I'll just take the numbers that are there, and work it out just the way the question says.
Distance = (14.75 km/s) x (4.25 hours) x (3,600 sec/hour)
Distance = (14.75 x 4.25 x 3,600) (km-hr-sec/sec-hr)
Distance = 225,675 km (a little more than half-way to the Moon)