3 dice r rolled and a,b,c obtained.find the probability that a.b+c is even.

• answer should be 1/2.
  case 1- when c is even then it is necessary for the product of a & b to be even. and for the product of a & b to be even again there are two ways viz. a & b both even, one odd one even and lastly one even one odd.
  case 2- when c is odd it is necessary for the product of a & b to be also odd. the product of a & b can be odd only when both a & b are odd.
  
  when one solves the probability of getting a.b + c to be even is 108/216 which is 1/2.
  
  as far asi have solved it should be the answer :)
• 11 years agoHelpfull: Yes(28) No(4)
• cas1-p for a.b is even is 3/4 and c to be even is 1/2....total probability is 3/8
  cas2-p for a.b is odd is 1/4 and c to be odd is 1/2.....total probability is 1/8
  so total probability to be a even no is 3/8+1/8=1/2
  
• 11 years agoHelpfull: Yes(16) No(0)
• answer should be 2/3
  
  explanation:
  
  case 1- when c is even then it is necessary for the product of a & b to be even. and for the product of a & b to be even again there are two ways viz. a & b both even, one odd one even and lastly one even one odd.
  case 2- when c is odd it is necessary for the product of a & b to be also odd. the product of a & b can be odd only when both a & b are odd.
  
  when one solves the probability of getting a.b + c to be even is 144/216 which is 2/3
  
  as far asi have solved it should be the answer :)
• 11 years agoHelpfull: Yes(10) No(6)
• a b c a.b+c
  odd odd odd even
  odd odd even odd
  odd even odd odd
  odd even even even
  even even even even
  even even odd odd
  even odd even even
  even odd odd odd
  
  probability of a.b+c even is ====(4/8)==1/2
• 11 years agoHelpfull: Yes(6) No(0)
• 108/216=1/2
• 11 years agoHelpfull: Yes(5) No(0)
• it should be 3/8. since we have 3 cases for the above problem as:- o*o+o, e*e+e, e*o+e. if we see for the probability of all three cases it comes to be 1/2*1/2*1/2= 1/8 for 1st and same for rest and addition of all three cases will give the ans as 3/8...
  
• 11 years agoHelpfull: Yes(4) No(3)
• case1:EVEN from first 2 dice(a.b)=27/36=3/4
  and EVEN from 3rd dice:1/2
  So, total:3/4x1/2=3/8
  case2:ODD from first 2 dice(a.b)=9/36
  ODD from 3rd dice:1/2
  so,total:1/2x1/4=1/8
  TOTAL:1/8+3/8=1/2
• 11 years agoHelpfull: Yes(3) No(0)
• 4/216=1/54
  
• 11 years agoHelpfull: Yes(1) No(4)
• possible outcome = 57
  required probability = 57/6*6*6
• 11 years agoHelpfull: Yes(1) No(2)
• P(a.b BEING EVEN)=27/36 -->1
  P(c BEING EVEN)=3/6 -->2
  P(a.b+c BEING EVEN)=(27*3)/(36*6)=3/8
• 11 years agoHelpfull: Yes(1) No(2)
• answer is 3/4.
• 11 years agoHelpfull: Yes(1) No(2)
• answer should be 108/216. zohair u hv done it wrong...
  
• 11 years agoHelpfull: Yes(1) No(0)
• 1/2 will be the answer !!!
• 11 years agoHelpfull: Yes(1) No(0)
• it should be 105/216
• 11 years agoHelpfull: Yes(0) No(0)
• ans is 1/2.....
• 11 years agoHelpfull: Yes(0) No(1)
• p1(a.b being even)=27
  p2(c being even)=3
  therefore p(a.b+c being even)=27*3/6^3
  again,
  p1(a.b being odd)=27
  p2(c being odd)=3
  therefore p(a.b+c being even)=27*3/6^3
  
  so, p(a.b+c being even)=27*3/6^3+27*3/6^3= 3/4 is d ans.
  
  
• 11 years agoHelpfull: Yes(0) No(0)
• i think answer is 135/216 as (1,2,2),(1,4,2),(1,6,2) will be even and like this there will 27 events that will occur with 1,3 and 5! and with (2,1,2),(2,2,2)(2,3,2)(2,4,2)(2,5,2),(2,6,2) are possble and like this for 2 there are 36 events so for 2,4,6 no of events =36*3=108.so answr will be (108+27)=135/216
• 11 years agoHelpfull: Yes(0) No(0)
• 162/216= 3/4 ans
• 11 years agoHelpfull: Yes(0) No(4)