A toy train produces at least 10 different tunes when it moves around a circular toy track of radius 5 meters, at
10 meters per minute. However, the toy train is defective and it now produces only two different tunes at
random. What is the probability that the toy train produces 3 music tunes of the same type (1 in _____ ) ?
(a) 3 (b) 9 (c) 8 (d) 4

• the answer seems like 1/8... but it actually is 1/4...
  
  the probability for the first time is 1 as any song can come
  probability for second time is 1/2, as first song must repeat...
  so, net probability = (1 * (1/2) * (1/2)) = 1/4
  
  the qn can also be considered as how many 3 digit binary numbers are there with the same digits... the answer is ofcourse 1/4 again (000 and 111, 2 cases out of 8 possible chances)
• 13 years agoHelpfull: Yes(71) No(34)
• 1/2^3=1/8 but here der r two types of tone and we need to find the odds of d train of two tones to form 3 tones consequently so 2*1/8= 1/4 so ans is 4
• 13 years agoHelpfull: Yes(35) No(1)
• (1/2)^3 + (1/2)^3=1/4 so ans is 4
• 13 years agoHelpfull: Yes(20) No(6)
• CLEARLY FOR THIS TYPE OF QUESTIONS FOLLOW A SHORTCUT RULE....
  SEE HOW MANY SOUNDS ARE PRODUCED AFTER DEFECTIVE 2....SO (1/2)..
  3 MUSIC TONES SO (1/2)^3=(1/8)
• 13 years agoHelpfull: Yes(18) No(29)
• so, answer is (d) 4
• 13 years agoHelpfull: Yes(9) No(21)
• (d) 4
• 13 years agoHelpfull: Yes(8) No(6)
• 1/2^3=1/8,(b) ans
• 13 years agoHelpfull: Yes(3) No(11)
• 1/2^3+1/2^3=1/4
  ans=4
• 11 years agoHelpfull: Yes(2) No(0)
• 8
• 13 years agoHelpfull: Yes(1) No(10)
• ans is 1/2*1/2*1/2=1/8.
• 13 years agoHelpfull: Yes(1) No(13)
• A toy train produces at least 10 different tunes when it moves around a circular toy track of radius 5 meters at 10 meters per minute. However , the toy train is defective and it now produces only two different tunes at random. What are the odds that the toy train produces for consecutive music tunes of the same type?
  
  
• 11 years agoHelpfull: Yes(1) No(5)
• trick = 2 type diference tunes so (1/2)^3 =1/8
  then 1/8 or two type of tunes i/8*2 =1/4
• 4 years agoHelpfull: Yes(0) No(0)