General Maths question (1 Viewer)

[cute-teddy]

hi.
Can someone plz help me with this question its financial expectation: A fair die is thrown. what are the financial expectations of theses games?
a)Six wins $50 and not a six loses $25.
b)Een number wins $20 and an odd number loses $15.
(this question is not a multiple choice question)

And another one is applicaion of probability which is expected outcomes. 1) Two cards are selectec at random from a normal playing pack with replacement. This experiment is repeated 2704 times with the cards being replaced each time.
a)What is the expectednumbers of times the result would be two spades?
b)What is the expectednumbers of times the result would be two aces?

2)There are 240 families with threee children.
a)how many of these families are expeced to have three boys?

 

[The Sped]

its not that hard...

 

[mashups]

1-a) = (1/6 x $50) - (5/6 x $25)
= a loss of $12.50, im pretty sure how that one is done.

b) = (3/6 x $20) - (3/6 x $15)
= a gain of $2.50
i have no idea how to do the other questions, maybe with a probability tree?

 

[madharris]

for the last question You probably have to find out the percentage of having 3 boys
i.e. 1/8

then times it by 240

 

[cute-teddy]

for the last question how did you get 1/8?

 

[Kat92]

Yep.. same answers. (Although I simplified the 3/6 but still gives the same answer)

For the last question you need to figure out the sample space: {BBB, BBG, BGB, BGG, GBB, GBG, GGB and GGG} only one combination of 3 boys is possible so you have 1/8 multiplied by the 240 to give 30 families. Probability tree as mentioned above would also work.

As for your other question.. that one takes a bit longer to work out (But it follows the sample principles).

 

[Kat92]

for the last question how did you get 1/8?

See my explanation- hopefully that helps!

 

[cute-teddy]

thank you

 

[Kat92]

thank you

Not a problem. You are welcome!

 

[cute-teddy]

thanks for your help everyone