Question
What is the probability oi rolling a total of 7 in two rolls of a standard die if you get an even number of the first roll?
Could someone please help me? Thanks
Could someone please help me? Thanks
Answers
PsyDAG
Even number can be either 2, 4 or 6. There is 1/6 chance for each one.
If previous was a 2, a 5 would = 7 (1/6 * 1/6) = 1/36
If previous was a 4, a 3 would = 7 (1/6 * 1/6) = 1/36
If previous was a 6, a 1 would = 7 (1/6 * 1/6) = 1/36
Either-or probability is found by multiplying the individual probabilities, 3/36.
If previous was a 2, a 5 would = 7 (1/6 * 1/6) = 1/36
If previous was a 4, a 3 would = 7 (1/6 * 1/6) = 1/36
If previous was a 6, a 1 would = 7 (1/6 * 1/6) = 1/36
Either-or probability is found by multiplying the individual probabilities, 3/36.
mae
you roll a number cube, what are the odds in rolling a 1 or 4?
Xorgate
The question needs to be understood in a slightly different way. It is 'given' that the first roll was an even number. Hence the probability of a 2 is 1/3, for 4 is 1/3 and for 6 it is 1/3
If previous was a 2, a 5 would = 7-> 1/3 * 1/6 = 1/18
If previous was a 4, a 3 would = 7 -> 1/3 * 1/6 = 1/18
If previous was a 6, a 1 would = 7 -> 1/3 * 1/6 = 1/18
Any one of the above possibilities will result in desired outcome. It is an 'OR' situation. Hence add the possibilities to get 3/18 = 1/6
If previous was a 2, a 5 would = 7-> 1/3 * 1/6 = 1/18
If previous was a 4, a 3 would = 7 -> 1/3 * 1/6 = 1/18
If previous was a 6, a 1 would = 7 -> 1/3 * 1/6 = 1/18
Any one of the above possibilities will result in desired outcome. It is an 'OR' situation. Hence add the possibilities to get 3/18 = 1/6