7th grade math?

Question

i'm not good at math please help me out here:A number cube is thrown 280 times. Predict how many times it will show a 3.


and another one:Two number cubes are rolled. If the total of the cubes is even, then player A receives 2 points. If the cubes total to 5, then player B receives 9 points. Find the expected value for each layer, and determine if the game is fair.

Answer 1

With 6 outcomes for each throw, you would expect 3 to occur 280/6 = 46.67 times.

With 2 dice, there are 36 possible combinations per throw.
Odd + odd = even (9 ways per throw)
Even + even = even (9 ways per throw)
Odd + even = odd (18 ways per throw)
A therefore expects to get 2 points on 1/2 of the trows.
Expected score 1 point per throw.

5 can be scored as 4+1, 3+2, 2+3 or 1+4.
4 ways out of 36 meet this requirement.
B therefore expects to get 9 points on 1/9 of the throws.
Expected score 1 point per throw.

The game is fair.

Answer 2

if the number cube is a standard 1 to 6, like playing dice then:

a 3 has a 1 in 6 chance of rolling so in 280 rolls it should theoretically come up 280x(1/6) times or 46.667 or 47 times but that doesn't happen in real life.

even dice are rolled 1 in 2 times or half the time so A's chances are 50/50
B's chances are 4 out of 36 or 1 in 9 (4 possible ways to make a 5 with 2 dice out of 36 possible rolls)


Now, is the game fair?

yes because 9(1/9)=1 for player B and 2(1/2)=1 for A so they both have the same reward value.

Answer 3

try this:

it's hardly 7th grade stuff.

if you get stuck send me an e-mail.

Answer 4

Whoah in 7th grade we didn't do that hah!