Answer:
Rate of plane in still air = P = W (t1 +t2)/ (t1-t2)
Rate of wind in still air = W = P (t1 - t2)/(t1 + t2)
Explanation:
Assuming speed of plane are the same on both trips
Rate (D/t1) = (P-W).... EQU 1 going from city a to b
Rate (D/t2) = (P +W)...Equ2 going back to city a
Where t1 is not equal to t2
Where D=distance between two cities
P &W are the speed of plane and wind
t1 &t2 = time taken for travel
Equ 1 & equ 2 becomes
D = ( P - W ) t1.. equ3
D = ( P + W ) t2 equa4
Equating equ 3 and 4
Pt1 - Wt1 = Pt2 +Wt2
P ( t1 - t2) = W ( t1 + t2)
Rate of plane in still air = P = W (t1 +t2)/ (t1- t2)
Rate of wind in still air = W = P (t1 - t2)/(t1 + t2)