Question

cConsider a game in which players roll a number cube to determine the number of points earned. If a player rolls a prime number, that many points will be added to the player’s total. Any other roll will be deducted from the player’s total. What is the expected value of the points earned on a single roll in this game?

Answer 1

Remember, we're dealing with a cube, so that means there are a total of six sides. Also keep in mind that prime numbers are 1, 3, and 5.

Answer 2

also 2 is a prime number

Answer 3

So that leaves 4 and 6 as numbers that deduct amounts. Therefore, it is more likely that you will have a positive score than a negative score on your first roll.

Answer 4

so it would be 5/6?

Answer 5

you would have a 2/3rds chance of getting a positive score, and a 1/3rd chance of getting a negative score. Does that make sense?

Answer 6

oh yeah okay so the answer would be 1/6 because you reduce it. Correct?

Answer 7

Actually, originally, since there are six sides in a cube, and four sides that will give you a positive score and 2 sides that would give you a negative score, the ratios are 4/6 and 2/6, but I've reduced them down to 2/3 and 1/3. You cannot reduce these ratios any further

Answer 8

my options are:
A. -5/6
B. -1/6
C. 1/6
D. 5/6

Answer 9

what exactly is a single roll in the game? Like do they mean one roll, or one round?

Answer 10

i think they mean one roll

Answer 11

because based from the info. in this problem, it's hard to tell what the exact value would be. However, because 5 and 1 result in positive points, I do believe it would be C.

Answer 12

okay thank you