How can my answer be incorrect if I haven't even figured it out yet ? ?
The volume of a cylinder is (pi) (radius²) (height, length, or depth).
The pool's diameter is 8m, so its radius is 4m .
The volume of the pool is (pi) (4m)² (1.6 m) = 25.6 pi m³ .
Filling it at the rate of 11 m³/hr, it will take
(25.6 pi / 11) = 7.308... hours to fill it to the brim.
Rounded to the nearest hour, that's 7 hours.