Four wheels moving 12, 24, 20 and 30 revolutions in a minute starting at a certain point on the circumference downwards. After what interval of time will they come together again in the same position ?

• 30 sec.
  
  For 1 revolution four wheel takes 60/12=5 sec, 60/24=2.5 sec, 60/20=3 sec, 60/30=2 sec respectively and LCM of (5, 2.5, 3, 2) = 30.
  So all the wheels will come together in same position after 30 sec.
• 6 years agoHelpfull: Yes(2) No(0)
• 30 sec
  LCM of (60/12 ,60/24,60/20,60/30)
• 6 years agoHelpfull: Yes(2) No(0)
• X/y=1/3,then x^2+y^2/x^-y^2=?
• 6 years agoHelpfull: Yes(1) No(0)