407  Stamp
How many stamps? 1

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There are 220 stamps which are 7-cent stamps and 8-cent stamps. Altogether they cost 1640 cents. How many 7-cent stamps are there?



There are 140 stamps which are 3-cent stamps and 7-cent stamps. Altogether they cost 660 cents. How many 3-cent stamps are there?



There are 170 stamps which are 5-cent stamps and 6-cent stamps. Altogether they cost 940 cents. How many 5-cent stamps are there?



There are 210 stamps which are 6-cent stamps and 4-cent stamps. Altogether they cost 1100 cents. How many 6-cent stamps are there?



There are 180 stamps which are 7-cent stamps and 6-cent stamps. Altogether they cost 1170 cents. How many 7-cent stamps are there?



There are 120 stamps which are 7-cent stamps and 3-cent stamps. Altogether they cost 640 cents. How many 7-cent stamps are there?



There are 170 stamps which are 3-cent stamps and 5-cent stamps. Altogether they cost 690 cents. How many 3-cent stamps are there?



There are 230 stamps which are 7-cent stamps and 9-cent stamps. Altogether they cost 1790 cents. How many 7-cent stamps are there?



There are 200 stamps which are 3-cent stamps and 8-cent stamps. Altogether they cost 950 cents. How many 3-cent stamps are there?



There are 200 stamps which are 8-cent stamps and 9-cent stamps. Altogether they cost 1700 cents. How many 8-cent stamps are there?



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407    120 80 80 130 90 ( 500 )   70 80 140 130 100 ( 520 )   [[ 1020 ]]