A bamboo plant grows 15 centimeters in 4 hours. At what average speed does the plany grow
always divide the time by the length-
S(avg spped)=L/T
this would give you per hour. to get per day, multiply 24
...I assume you meant 'plant' rather than 'plany'...
15 cm / 4 hr = 3.75 cm/hr = 90 cm/day