Answer:
Both works will be repeated at 840km
Explanation:
Given
Fills Petrol = Every 84km
Change Mobil = Every 120km
Required
Determine the distance where both works are done at the same time
This solution to this question is to solve for the LCM of 84 and 120
Start by factoring 84
Then, 120
Then the LCM is as follows;
Hence, both works will be repeated at 840km