Bea was overweight and her doctor told her to lose 45 kg. If she loses 15 kilograms on the first week, 12 kilograms on the second week, and 9 kilograms on the third week. How much will
he lose on the fifth week?

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.