721  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 1290 cents. How many 7-cent stamps are there?



There are 210 stamps which are 6-cent stamps and 9-cent stamps. Altogether they cost 1650 cents. How many 6-cent stamps are there?



There are 170 stamps which are 8-cent stamps and 7-cent stamps. Altogether they cost 1280 cents. How many 8-cent stamps are there?



There are 180 stamps which are 6-cent stamps and 3-cent stamps. Altogether they cost 930 cents. How many 6-cent stamps are there?



There are 270 stamps which are 8-cent stamps and 3-cent stamps. Altogether they cost 1560 cents. How many 8-cent stamps are there?



There are 250 stamps which are 6-cent stamps and 9-cent stamps. Altogether they cost 1890 cents. How many 6-cent stamps are there?



There are 200 stamps which are 6-cent stamps and 4-cent stamps. Altogether they cost 1080 cents. How many 6-cent stamps are there?



There are 230 stamps which are 6-cent stamps and 8-cent stamps. Altogether they cost 1540 cents. How many 6-cent stamps are there?



There are 210 stamps which are 8-cent stamps and 4-cent stamps. Altogether they cost 1200 cents. How many 8-cent stamps are there?



There are 200 stamps which are 6-cent stamps and 7-cent stamps. Altogether they cost 1290 cents. How many 6-cent stamps are there?



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721    120 80 90 130 150 ( 570 )   120 140 150 90 110 ( 610 )   [[ 1180 ]]