Damians conservation club wants to plant 640 seedlings. They have 172 seedlings that they still need to plant to meet their goal. How many seedlings have they planted so far?

The first one, i believe, would be correct. all the others have one thing in common, and that's that they have repeating numbers. in the second one, x and y have repeating 6's and 3's, and in the third, x and y have repeating 6's as well. in the last one, there are repeating 3's. the first one has no repeating numbers.