# 2 gears one with 12 teeth and other one with 14 teeth are engaged with each other. One teeth in smaller and one tooth in bigger 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
asked Oct 31, 2013 in TCS

Now LCM (12, 14) = 84. So to cover 84 cm, the first gear has to rotate $\displaystyle\frac{{84}}{{12}}$ = 7 rounds (the second gear rotates 84 / 14 = 6 rounds as it is bigger)