Without delay, let's solve this. We've got 600 and we will be multiplying it by 3, that is, adding 600 to itself 3 times.
Step 1: 0 + 600 = 600
Step 2: 600 + 600 = 1200
Step 3: 1200 + 600 = 1800

So, 600*3 = 1800