The probability of rolling a 6 on the 1st roll is 
, since there is only 1 out of 6 sides of the dice that has six pips.
The probability of rolling an odd number is
, since there are 3 out of 6 sides of the dice that has an odd number of pips. 
Then the probablity of both events happening one after another is
. You have to multiply both probabilities of the events: 
The probability of rolling an odd number is
Then the probablity of both events happening one after another is
