probability

chukwu wrote 3 letters l1,l2,l3 and envelopes E1,E2,E3(of the same size and colour )addressed to three companies .if the letters are to be correctly addressed , l1 should go into E1, L2 TO E2 AND L3 TO E3. CHUKWU'S SECRETARY IN A HURRY TO CLOSE FOR THE DAY , RANDOMLY INSERTED THE LETTERS INTO THE ENVELOPES .

1) LIST ALL THE NINE POINTS IN THE SPACE ,USING THE CONVENTION L1 TO E1 TO MEAN LETTER L , GOES INTO ENVELOPE E , THUS E1 IS A POINT IN THE SAMPLE SPACE.

2) COMPUTE THE PROBABILITY THAT ALL THE LETTERSN GO INTO THIER CORRECT ENVELOPES
3)WHAT SI THE PROBABILITY THAT BOTH L1 AND L2 DO NOT GO INTO THEIR CORRECT ENVELPOES