Since volunteers can be of any sexe (no precision given in your problem), then we can consider the question as how many group of 6 we can make with 12 persons:
It's a combination of 6 chosen among 12
¹²C₆ = (12!)/(6!).(12-6!)
²C₆ = (12!)/(6!).(6!)<span>
</span>¹²C<span>₆</span> = 924 Ways
Card K is reflected over the y-axis; while card N is reflected over the x-axis
You can use the simple interest formula

We need P, which is the primary (or principal) investment, and we know that:
rate = 3% (0.03)
time = 7
i = $25000
So, just plug in and solve:


The company needs to invest $5250 today, to make $25000 in 7 years.
We can rewrite the asked question like this:

wherein X_1 and X_2 are random variable with the same given normal distribution. Then mean of

is zero and the variance
can be computed like this:

So, the random variable

follows a normal distribution
with means 0 and standard deviation 9.6.
The median of the law N(0,9.6) is 0.
So the expected difference of the score is 0.