A BIRD IS FLYING FROM AN OAK TREE TO A PINE TREE IN A SPEED OF 6 K...

23. A bird is flying from an oak tree to a pine tree in a speed of 6 Km/h. On her way back, she flew at a speed of 4 Km/h, thus, the trip lasted 4 hours more. What is the distance between the trees? (In Km)