Respuesta :

de3166
3 packs of cards and 2 packs of envelopes
the lowest common multiple of 6 and 9 is 18

18/6 = 3....she needs 3 packs of cards
18/9 = 2...she needs 2 packs of envelopes

so by buying 3 packs of cards and 2 packs of envelopes, she will have 18 of each