If the angle of elevation of a cloud from a point P which is 25m...

$tan {30}^{o} = \dfrac{x - 25}{d}$

and $tan {60}^{o} = \dfrac{x + 25}{d}$

$⇒ \dfrac{tan {30}^{o}}{tan {60}^{o}} = \dfrac{x - 25}{x + 25} ⇒ \dfrac{1}{3} = \dfrac{x - 25}{x + 25}$

$⇒ x + 25 = 3x - 75$

$⇒ 2x = 100 ⇒ x = 50m$