Alan mows lawns in the summer to make money. He knows that, on average, he can mow 1/2 of a lawn in 1 1/4 hours. Calculate his average mowing rate in lawns per hour.

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.

Google it that might work

The answer is biodiversity resulting from new ancestors.