# (SOLVED) probability

**Discipline:** Mathematics

**Type of Paper:** Question-Answer

**Academic Level:** Undergrad. (yrs 3-4)

**Paper Format:** APA

**Pages:**1

**Words:**275

Question

1. A manufacturer puts tires on two cars(four tires each). Each tire has a 10% probability of being flat. Assume the manufacturer puts four tires on one car first, then another four on the second car. What's the probability that one car has no working tires?

2.Let X1, X2...X100 be all independent Bernoulli variables, which take a value of 1 with probability0.5. Estimate the probability that X1,X2,...X100 <60.

**Expert Answer**

#1.

For a car, p = 0.1 and n = 4

Probability of all tyres non working = 0.1^4 = 0.0001

Probability that either car has all tyres non working

Required probability = 2C1 * 0.0001 * (1-0.0001) = 0.0002

#2.

This is a binomial problem with p = 0.5 and n = 100

lets find the probability P(X < =59)

=BINOM.DIST(59,100,0.5,TRUE)

Required probability = 0.9716