2 gears. one with 12 teeth and the other one with 14 teeth are engaged with each other. One tooth in smaller gear and one tooth in bigger gear are marked and initially those 2 marked teeth are in contact with each other. After how many rotations of the smaller gear with the marked teeth in the other gear will again come into contact for the first time?
a. 7
b. 12
c. Data Insufficient
d. 84

• Assume the distance between the teeth is 1 cm. Then the circumference of first gear is 12 cm and the second is 14 cm.
  Now LCM (12, 14) = 84.
  So to cover 84 cm, the first gear has to rotate 84/12 = 7 rounds
  (the second gear rotates 84 / 14 = 6 rounds as it is bigger)
• 10 years agoHelpfull: Yes(35) No(0)
• The number of rotations of the two wheels will be inversely proportional to the number of teeth the wheel has. Since the ratio of the number of teeth is 6 : 7, the ratio of the number of rotations of the wheels is 7 : 6. The two marked teeth will be together only after both the wheels have done an integral number of rounds. Thus, smaller wheel will have done 7 rounds.
• 10 years agoHelpfull: Yes(8) No(0)
• 84
  take the LCM of 12 and 14
• 10 years agoHelpfull: Yes(2) No(0)
• lcm of 12 and 14 is 84;
  84/12=7
  answer is 7
• 9 years agoHelpfull: Yes(2) No(1)
• plzzz provid crct sltn
• 10 years agoHelpfull: Yes(0) No(0)
• distance b/w the teeth is not given so the data is insufficient.
• 10 years agoHelpfull: Yes(0) No(0)