You roll 2 number cubes each labeled 1 to 6 what is probabilty you will roll a double?

The probability is based on the second cube having 6 sides. No matter what you roll on the first cube, the chance of rolling "doubles" is 1 in 6! Now if you ask, what is the chance in rolling a specific set of doubles, the chance is 1 in 6 times 1 in 6 times, or 1 in 36 ...