Answer:
<h3>78miles/hour</h3>
Step-by-step explanation:
If a helicopter flies 312 miles against the wind in 2 hours, the speed of the helicopter in air is expressed as shown;
Speed = Distance/Time
Speed = 312miles/2hours
Speed = 156miles/hr
The speed of the helicopter against the wind is 156miles/hr
If it can fly 468 miles in the same amount of time, the speed during this time at this distance will be;
speed = 468 miles/2hours
Speed = 234miles/hr
The speed of the helicopter in still air = Speed while flying - Speed while against the wind
The speed of the helicopter in still air = 234miles/hr - 156miles/hr
The speed of the helicopter in still air = 78miles/hour
