2520
= 10 * 252
= 2 * 5 * 2 * 126
= 2 * 5 * 2 * 2 * 63
= 2 * 5 * 2 * 2 * 7 * 3 * 3
= 2^3 * 3^2 * 5 * 7
I suppose this is in reference to the chance?
The chance of choosing either red or blue marbles is 50/50 considering that there if four of each type in the bag.
The person chose 2 times, and each time go a red marble. The chance of choosing either is still 50% and they are both equally likely to get chosen.
I'm not sure if i am correct but i would say
[ 0,1 ]
N and n+2 because if n=1 then you do 1+2 and that equals 3. So then you have 1,3