David paints 3 rooms in 7 hours at the same pace how long would it take him to paint 15 rooms

Aparallel system functions whenever at least one of its components works. consider a parallel system of n components, and suppose each component works independently with probability 0.5. find the conditional probability that component n works given that the system is working

Can some one explain this i got sent this. is this a threat i’m scared

What is the radius of the cone in the diagram? round your answer to the nearest whole number