All questions must be answeredNot just one or two Please don

Solution

NOTE: WE ARE SUPPOSE TO ANSWER ONE QUESTION AT A TIME, SO I WILL GIVE U SOLN OF 3 FOR REST REPOST THE QUESTION

3)A) CHOOSING ANY NUMBER HAS SAME PROBABILITY = 1/10

ATLEAST 1 ZERO MEANS 1,2,3,4

= 4* 10C4*(1/10)^10

NOW U HAVE TO GET THE COMPLEMENT OF THIS SO 1 -4* 10C4*(1/10)^10 = 0.99

3B)NONE DIGIT IS 7 SO WE WILL HAVE 9 OPTIONS TOTAL

PROBABILITY WILL BE 9C4*(1/9)^9

THE COMPLENT WILL BE 1 - 9C4*(1/9)^9 = 0.97