The other tutor doesn't have a clue as to what you want. Starting at the top row with 2 logs, then three logs, etc., it's, , Multiply both sides by 2 to clear the fraction: 4030 = n(3+n) 4030 = 3n+n² 0 = n²+3n-4030 To factor that we have to find two integers that multiply to give 4030 and have a difference of 3. That's such a small difference in comparison to 4030 they would have to both be near the square root of 4030 which is about 63.5. 63 doesn't go evenly into 4030, but 62 does. so 62×65=4030 so it factors this way: 0 = (n-62)(n+65) n-62 = 0 n+65 = 0 n = 62 n = -65 <-- ignore since negative So there are 62 rows of logs. The bottom row of logs has as many logs as the 62nd term. Now we find what the 62nd term is logs. Edwin