Anyone know how to do these with work shown? thanks so much! :)?

Question

5) How many different varieties of one topping pizzas can be made if you have the following choices:
Size: small, medium, or large
Crust: thin n' crispy, hand-tossed, or pan
Toppings: there are 10 toppings (cheese is automatic)

8) The success rate for a certain type of surgery is 85%. The surgery is performed on 6 patients. (Assume the outcomes of surgeries are independent of each other)

a) Find the probability that the surgery is successful for exactly 3 patients.

b) Find the probability that the surgery is successful for fewer than four patients. 

c) Find the probability that the first unsuccessful surgery is the 3rd surgery.


3) At Mr. Burn's Springfield Nuclear Power Plant, safety gadgets are checked every day. Smithers checks 75% of them, Homer Simpson checks the rest. Smithers overlooks a defective gadget with probability 0.16. Homer misses 80% of the defective gadgets he checks.

a) What is the probability that a defective safety gadget is overlooked?

b) If there is indeed an accident at Mr. Burns plant due to a defective safety gadget, what is the probability that Homer Simpson is responsible

Answer

5) 3 x 3 x 10 = 90 different varieties

i'm not sure about the rest sorry

Answer

8:the success is 85/100
not success is 15/100
by the rule a) =0.85*0.15/0.15 for one patient because it is independent 
i think for 3 =0.85*3/0.85*6
b)for 1.for 2.for3 just 
for 1 0.85/6*0.85+for2  0.85*2/0.85*6+for3  0.85*3/0.85*6
c)=0.15/0.15*6
i think like this

Anyone know how to do these with work shown? thanks so much! :)?

Responses (2)