Question

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

Answer 1

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

Answer 2

`= 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`