Question 5
At a height of $h$ metres above sea level, the distance $d$, in kilometres, to the visible horizon is given approximately by the formula $d = 8\sqrt{\frac{h}{5}}$. A mountaineer on the side of Table Mountain can see a distance of $80$ kilometres to the horizon. How high, in metres, is the mountaineer above sea level?
(A) 1 000 (B) 500 (C) 650 (D) 250 (E) 400
(A) 1 000 (B) 500 (C) 650 (D) 250 (E) 400