You are offered the following gamble: Flip two fair coins. If at least one head comes up, you win $12. If not, you lose $24. What is the expected value of this gamble?

$3

Step-by-step explanation:

Flipping two fair coins :

Sample space :

{TH, HT, TT, HH}

Atleast one head = 12

If not = - 24

Probability of atleast one head = 3/4

If not ; probability of 2 tails = 1/4

Hence,

X 12 -24

P(x) ___0.75 0.25

Expected value for of gamble E(x) :

Σx * p(x) = (12 * 0.75) + (-24 * 0.25)

E(x) = 9 - 6

E(x) = 3

Expected value of gamble = $3

answer: the correct one is a

step-by-step explanation:

fabric (square meters)                   cloaks

7                                                           21

4/3                                                         4

step-by-step explanation:

we are told that harry needs 2 square meters of fabric for every 6 wizard cloaks he makes.

1. first of all we will find how many cloaks can be made from 1 square meter of fabric by dividing 6 by 2.

we can see that 3 cloaks can be made from 1 square meter of fabric. now we will multiply 3 by 7 to find number of cloaks made from 7 square meters of fabric.

therefore, harry will make 21 cloaks from 7 square meters of fabric.

2. let us find how many square meters of fabric will be needed to make 4 cloaks.

first of all we will find fabric needed for 1 cloak by dividing 2 by 6.

we can see that fabric needed for 1 cloak is   square meter. now we will multiply   by 4 to find fabric needed for 4 cloaks.