309  Stamp
How many stamps? 1

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There are 130 stamps which are 7-cent stamps and 9-cent stamps. Altogether they cost 1010 cents. How many 7-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 230 stamps which are 4-cent stamps and 7-cent stamps. Altogether they cost 1160 cents. How many 4-cent stamps are there?



There are 230 stamps which are 3-cent stamps and 9-cent stamps. Altogether they cost 1470 cents. How many 3-cent stamps are there?



There are 210 stamps which are 4-cent stamps and 9-cent stamps. Altogether they cost 1190 cents. How many 4-cent stamps are there?



There are 280 stamps which are 3-cent stamps and 7-cent stamps. Altogether they cost 1360 cents. How many 3-cent stamps are there?



There are 160 stamps which are 3-cent stamps and 4-cent stamps. Altogether they cost 570 cents. How many 3-cent stamps are there?



There are 250 stamps which are 5-cent stamps and 8-cent stamps. Altogether they cost 1640 cents. How many 5-cent stamps are there?



There are 150 stamps which are 3-cent stamps and 6-cent stamps. Altogether they cost 690 cents. How many 3-cent stamps are there?



There are 240 stamps which are 4-cent stamps and 8-cent stamps. Altogether they cost 1360 cents. How many 4-cent stamps are there?



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309    80 140 150 100 140 ( 610 )   150 70 120 70 140 ( 550 )   [[ 1160 ]]