MHB Dice Probability (5 Sided Dice and 6 Sided Dice)

[coolguy56]

hi I am stuck on a question and was wondering if anyone could help me out (show a working solution/steps) to the problem.

here's the question:

Las Vegas Casino has introduced a new gambling game. A five-faced die A has numbers 1, 2, 2, 2
and 5 on its faces. This die and a normal die B (i.e. one with the numbers 1 to 6 on its six faces) are
rolled together. Which of the following choices offers you the highest chance of winning? a. Rolling a 2 with A and either a 2 or 4 with B? = My answer: 3/5 x 2/6 = 1/5b. Rolling a 1 with A and any number other than a 1 with B? My answer: 1/5 x 5/6 = 1/6c. Rolling two numbers on A and B such that their total is 7? This is the one I am stuck on! and therefore do not know which option offers you the highest chance of winning. In each case, if you win, what is the probability that you rolled a 2 with die B? Also, this question too!

Many Thanks

 

[Siron]

For question $c$ you have to ask yourself: how many possible outcomes are there to make a sum of $7$? In other words, how many combinations $a+b = 7$ are possible where $a$ is a number generated by rolling die A and $b$ a number generated by rolling die B. For example you could have $2$ and $5$ or $1$ and $6$ etc...