Respuesta :
Use LCM.
The LCM of 10 and 12 is 60. She has to buy 5 packs of straps to get 60 straps and 6 packs of buckles to get 60 buckles.
The LCM of 10 and 12 is 60. She has to buy 5 packs of straps to get 60 straps and 6 packs of buckles to get 60 buckles.