An aircraft flew 5 hours with the wind . the return trip took 6 hours against the wind . if the speed of the plane in still air is 490 miles per hours more than the speed of the wind , find the wind speed and the speed of the plane in still air

The speed of the plane in still air is 89.83 mph and the speed of air is 8.17 mph.

Step-by-step explanation:

Let the speed of the plane in still air is u mph and the speed of the wind is v mph.

Now, the aircraft flew 490 miles in 5 hours with the wind.  

Hence, ........ (1)

Now, the aircraft flew 490 miles in 6 hours against the wind.

So, ............ (2)

Now, adding equations (1) and (2) we get,

2u = 179.67

⇒ u = 89.83 mph

Now, from equation (1) we get,

v = 98 - u = 98 - 89.83 = 8.17 mph.

Therefore, the speed of the plane in still air is 89.83 mph and the speed of air is 8.17 mph. (Answer)

the answer is b