Step 1: As depreciating means decrease, the value of the car is decaying
Step 2 and step 3: You use the formula below to find the value of the car after 3 years (as the value is decaying the rate in the formula is substracting)
You can use number patterns to find the LCM of 120 and 360 by multiplying 120 by 1,2,3,4,5,6,and so on and do the same with 360 until you find the least number that they have in common.