Maths distance rate question: Please Help!?

Question

A man drove to the airport from home at an average speed of 30kph, where he boarded an helicopter and flew to corporate offices at an average speed of 60kph. The entire distance was 150km, the entire trip took 3 hrs. Find the distance from the airport to the corporate offices.

Answer 1

speed= distance / time; time = distance / speed

Let x be the distance from home to airport

let t1 be time taken to travel x

Let y be the distance from airport to office

let t2 be time taken to travel y

then

x + y = 150

t1 + t2 = 3 and t1 = 3 - t2

t1 = x / 30 and x = 30t1

t2 = y / 60 and y = 60t2

30t1 + 60t2 = 150 (from x+y=150)

t1 + 2t2 = 5            ( divide through by 30)

3 - t2 + 2t2 = 5

t2 = 5 - 3 = 2 therefore t1 = 1

from above y= 60t2

therefore y = 120

Answer 2

120 km