we know that
64.4 km/h-64 km/h-------> 0.4 km/h
the zebra is 0.4 km/h much faster
1 km---------> 3280.84 feet
0.4 km---------> X
X=0.4*3280.84-----------> 1312.336 ft
the zebra is 1312.336 ft/h much faster
1 hour----------> 3600 sec
then
1312.336 ft/ 3600 sec----------> 0.36 ft/sec
the answer is 0.36 ft/sec
