Two gift shops sell postcards. Each gift shop charges a fixed amount per postcard. The prices, in cents, for different numbers of postcards at the first gift shop are shown in the table below.
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1st gift shop:
120/4 = 30 cents each
180/6 = 30 cents each
390/13 = 30 cents each
2nd gift shop:
204/7 = 29.14 cents each
192/8 = 24 cents each
270 /9 = 30 cents each
360/10 = 36 cents each
so if both gift shops have a fixed price then the 9 post cards would be the answer since it matches 30 each like the 1st gift store