639  Stamp
How many stamps? 1

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There are 200 stamps which are 3-cent stamps and 6-cent stamps. Altogether they cost 870 cents. How many 3-cent stamps are there?



There are 210 stamps which are 6-cent stamps and 7-cent stamps. Altogether they cost 1380 cents. How many 6-cent stamps are there?



There are 200 stamps which are 3-cent stamps and 4-cent stamps. Altogether they cost 720 cents. How many 3-cent stamps are there?



There are 280 stamps which are 6-cent stamps and 8-cent stamps. Altogether they cost 1940 cents. How many 6-cent stamps are there?



There are 170 stamps which are 6-cent stamps and 4-cent stamps. Altogether they cost 880 cents. How many 6-cent stamps are there?



There are 170 stamps which are 7-cent stamps and 9-cent stamps. Altogether they cost 1370 cents. How many 7-cent stamps are there?



There are 230 stamps which are 3-cent stamps and 7-cent stamps. Altogether they cost 1210 cents. How many 3-cent stamps are there?



There are 190 stamps which are 3-cent stamps and 7-cent stamps. Altogether they cost 970 cents. How many 3-cent stamps are there?



There are 260 stamps which are 5-cent stamps and 3-cent stamps. Altogether they cost 1060 cents. How many 5-cent stamps are there?



There are 260 stamps which are 7-cent stamps and 5-cent stamps. Altogether they cost 1580 cents. How many 7-cent stamps are there?



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639    110 90 80 150 100 ( 530 )   80 100 90 140 140 ( 550 )   [[ 1080 ]]