Hola, alguien buena onda que me pueda ayudar: En una casa comercial hacen un descuento de un 15% de la mitad del precio marcado de una mercadería. Si la mercadería tiene un precio marcado de $600, ¿cuánto me descuentan?

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.