521  Stamp
How many stamps? 1

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There are 150 stamps which are 7-cent stamps and 4-cent stamps. Altogether they cost 900 cents. How many 7-cent stamps are there?



There are 210 stamps which are 4-cent stamps and 7-cent stamps. Altogether they cost 1170 cents. How many 4-cent stamps are there?



There are 180 stamps which are 4-cent stamps and 8-cent stamps. Altogether they cost 1000 cents. How many 4-cent stamps are there?



There are 150 stamps which are 6-cent stamps and 8-cent stamps. Altogether they cost 1060 cents. How many 6-cent stamps are there?



There are 130 stamps which are 7-cent stamps and 3-cent stamps. Altogether they cost 710 cents. How many 7-cent stamps are there?



There are 180 stamps which are 4-cent stamps and 3-cent stamps. Altogether they cost 630 cents. How many 4-cent stamps are there?



There are 200 stamps which are 5-cent stamps and 3-cent stamps. Altogether they cost 860 cents. How many 5-cent stamps are there?



There are 180 stamps which are 5-cent stamps and 8-cent stamps. Altogether they cost 1200 cents. How many 5-cent stamps are there?



There are 200 stamps which are 4-cent stamps and 9-cent stamps. Altogether they cost 1450 cents. How many 4-cent stamps are there?



There are 210 stamps which are 5-cent stamps and 9-cent stamps. Altogether they cost 1530 cents. How many 5-cent stamps are there?



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521    100 100 110 70 80 ( 460 )   90 130 80 70 90 ( 460 )   [[ 920 ]]