You have to find the probability that; if together both the dices are thrown, at-least from both, 1 shows a six, and from both 1 has to show 6.
1 1 5
-- + --- = -----
4 6 12
Is this the answer ?
Nope........you did it wrong there dude.
The question asked at least a six form both dices but exactly one six should be obtained.
Hence
probable results are :
1. 6 from biased die and any other number from unbiased die.
2. Any other number from unbiased die and 6 from unbiased die.
Probability : (1/4 x 5/6) + (3/4 x 1/6) =
1/3