In a class, there are 15 boys and 10 girls. Three students are selected at random. The probability that 1 girl and 2 boys are selected, is:
a)21/46
b)25/117
c)1/50
d)3/25

• a)21/46
  
  There are 3 combinations to get desired results
  BBG
  BGB
  GBB
  
  Hence probability that 1 girl and 2 boys are selected = 3* (15/25) *(14/24)*(10/23)= 21/46 ... option a)
• 12 years agoHelpfull: Yes(7) No(5)
• (10c1 * 15c2)/25c3 = 21/46
• 7 years agoHelpfull: Yes(4) No(0)
• answer :a
• 6 years agoHelpfull: Yes(0) No(0)
• 15 Boys and 10 Girls are there.
  3 Students are selected.
  Combinations are BBG,BGB,GBB
  Probability = 15c2*10c1/25c3 = 21/46
• 6 years agoHelpfull: Yes(0) No(0)
• (10C1+15C2)/25C3
  =1/50
• 6 years agoHelpfull: Yes(0) No(0)
• Let S be the sample space and E be the event of selecting 1 girl and 2 boys.
  
  Then, n(S)= Number ways of selecting 3 students out of 25
  = 25C3 `
  =(25 x 24 x 23)/(3 x 2 x 1)
  = 2300.
  n(E) = (10C1 x 15C2)
  =10 x(15 x 14)/(2 x 1)
  = 1050.
  P(E) =n(E)/n(S)=1050/2300 =21/46 .
• 6 years agoHelpfull: Yes(0) No(0)