The probability that a specific hydraulic actuator can be successfully repaired in the field, once it has failed, is estimated at 0.4. You are asked to optimize the shipment of a limited supply of spares and maintenance personnel. If 15 actuators have failed today, what is the probability that 

A) at least 10 are repairable? 

B) from 3 to 8 are repairable? 

C) exactly 5 are repairable?