Respuesta :

Answer:

5 days

Step-by-step explanation:

12/4 = 3 So this means that she sends 3 postcards a day.  

15/3 = 5 So she has to be on vacation 5 days in order to send 15 postcards.

Answer:

for sending 12 postcards she had to be on vacation for 4 days

for sending 1 postcard she would to be on vacation for 4/12=1/3 days

for sending 15 postcards she would to stay

1/3*15

5 days