There are two groups of subjects, one of which consists of 5 science subjects and 3 engineerign subjects and the other consits of 3 science and 5 engineering subjects. An unbaised die is cast. If number 3 or 5 turns up, a subject from group I is selected, otherwise a subject is selected from group II. The probability that an engineering subject is selected ultimately is

• The probability of gettting 3 or 5 in a die is 2/6 and others is 4/6.The probability of selecting engg fron 1st group is 3/8 and that of 2nd group is 5/8.Ans is ((2/6)*(3/8)) +((4/6)*(5/8))
• 12 years agoHelpfull: Yes(38) No(1)
• we need to select 1 from 2 subjects irrespective of group the probability is 1/2.
  
  now, if 3 is rolled then the probability is 1/2 * 3/8 = 3/16;
  
  now, if 5 is rolled then the probability is 1/2 * 3/8 = 3/16;
  
  now if other number is rolled then the probability is 1/2 * 5/8 = 5/16.
  
  add all 3/16 + 3/16 + 5/16 = 11/16 ans..
• 12 years agoHelpfull: Yes(0) No(16)