Answer: The government must destroy 52 units.
Explanation:
For the price floor be supported, we cannot have a demand higher than the supply (price will go up) and cannot have supply higher than demand (price will go down). 
Demand = supply keep the price floor. 
The government will have to purchase or destroy the excess supply.
p = 24
qd = 269 - 9p
qd = 269 - 9.24 = 53
qs = 9 + 4p 
qs = 9 + 4.24 = 105
qd = qs
105 - 53 = 52
The government must destroy 52 units.