These numbers form an arithmetic progression (AP). The first 3-digit number leaving a remainder of 2 when divided by 3 is 101 (101 = 3 33 + 2). The last such number is 998 (998 = 3 332 + 2). The common difference is 3. The number of terms is N = ((998 - 101)/3) + 1 = (897/3) + 1 = 299 + 1 = 300. The sum of an AP is (N/2) (First term + Last term) = (300/2) (101 + 998) = 150 1099 = 164850.