I roll a 6sided dice twice. What the propability to get the same number twice?

2 Answers
Jun 28, 2018

#1/6# as six of thirty six combinations have the same number.

Jun 28, 2018

# = 1/6 #

Explanation:

The probability of getting the same number each time is:

# = P("1 and 1" ) +P("2 and 2" ) + P("3 and 3" ) +P("4 and 4" ) #

# + P("5 and 5" ) + P("6 and 6" )#

The probability of getting one number on one dice is #1/6# as there is 6 different outcomes possible, and hence the probability of getting that same number in the second dice is also #1/6# as they are independent events, Hence probability of getting same on two occurrences is #1/6 xx 1/6 = 1/36 #

#=> = 1/36 + 1/36 + 1/36 + 1/36 + 1/36 + 1/36 = 6/36 = 1/6 #