To return to the bottom of the climbing wall, Rajan must climb down the total distance he climbed up. Since he climbed up 10 ft and then an additional 5 ft, he must climb down a total distance of 10 + 5 = <<10+5=15>>15 ft.
To return to the bottom of the climbing wall, Rajan must descend downwards. He can do this by climbing down the wall.
