One gear turns 33\frac{1}{3} times in a minute. another gear turns 45 times in a minute. initially, a mark on each gear is pointing due north. after how many seconds will the two gears next have both their marks pointing due north?

The first time they will both have completed full rotations is 3×5=15 Thus 15×1.8=27 rotations & 15×1 and 1/3=20 rotations.

Step-by-step explanation:

33 1/3 gear takes 1.8 sec to make one revolution and the 45 gear takes 1 and 333 seconds per revolution.