1a) You work part-time in an ice cream shop

Subject:MathPrice: Bought3

Share With

1a) You work part-time in an ice cream shop. You begin to take note of which ice cream flavors the customers who showed up today ordered. Out of the three flavors your shop offers, vanilla was chose by 9 customers, and raspberry by 4 customers. The third flavor remains untouched. Based on this observation, what is the probability that, of the next three customers, the first two will choose vanilla and the third one will choose chocolate?

(only round final answer to 2 decimal places, do not round intermediate numbers)

 

b) A robotic arm reaches into a box of manufactured parts and picks them out one by one for inspection. Once the item is inspected, if it is a defective it is discarded and if it passes the inspection, it is put on a conveyor belt and sent for further processing. Once the robotic arm either discards a part or puts one on the conveyor belt for further processing, it reaches into the box for the next part. A new box arrives and there are 55 parts in it. We know that this box contains 3 defective parts. what is the probability that the robotic arm will retrieve a defective part on the first time, but not on the second and third times it reaches into the box?

(express probability as a decimal number rounded to 2 decimal places)