478  Stamp
How many stamps? 1

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There are 170 stamps which are 7-cent stamps and 9-cent stamps. Altogether they cost 1330 cents. How many 7-cent stamps are there?



There are 190 stamps which are 8-cent stamps and 7-cent stamps. Altogether they cost 1400 cents. How many 8-cent stamps are there?



There are 140 stamps which are 7-cent stamps and 3-cent stamps. Altogether they cost 700 cents. How many 7-cent stamps are there?



There are 140 stamps which are 3-cent stamps and 5-cent stamps. Altogether they cost 540 cents. How many 3-cent stamps are there?



There are 220 stamps which are 8-cent stamps and 6-cent stamps. Altogether they cost 1500 cents. How many 8-cent stamps are there?



There are 250 stamps which are 6-cent stamps and 4-cent stamps. Altogether they cost 1280 cents. How many 6-cent stamps are there?



There are 170 stamps which are 6-cent stamps and 7-cent stamps. Altogether they cost 1100 cents. How many 6-cent stamps are there?



There are 180 stamps which are 6-cent stamps and 9-cent stamps. Altogether they cost 1410 cents. How many 6-cent stamps are there?



There are 150 stamps which are 7-cent stamps and 6-cent stamps. Altogether they cost 990 cents. How many 7-cent stamps are there?



There are 190 stamps which are 7-cent stamps and 8-cent stamps. Altogether they cost 1380 cents. How many 7-cent stamps are there?



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478    100 70 70 80 90 ( 410 )   140 90 70 90 140 ( 530 )   [[ 940 ]]