550  Stamp
How many stamps? 1

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There are 220 stamps which are 3-cent stamps and 7-cent stamps. Altogether they cost 1140 cents. How many 3-cent stamps are there?



There are 200 stamps which are 8-cent stamps and 5-cent stamps. Altogether they cost 1390 cents. How many 8-cent stamps are there?



There are 200 stamps which are 7-cent stamps and 9-cent stamps. Altogether they cost 1620 cents. How many 7-cent stamps are there?



There are 200 stamps which are 5-cent stamps and 6-cent stamps. Altogether they cost 1070 cents. How many 5-cent stamps are there?



There are 160 stamps which are 7-cent stamps and 3-cent stamps. Altogether they cost 840 cents. How many 7-cent stamps are there?



There are 230 stamps which are 7-cent stamps and 8-cent stamps. Altogether they cost 1730 cents. How many 7-cent stamps are there?



There are 210 stamps which are 3-cent stamps and 7-cent stamps. Altogether they cost 1150 cents. How many 3-cent stamps are there?



There are 150 stamps which are 7-cent stamps and 8-cent stamps. Altogether they cost 1120 cents. How many 7-cent stamps are there?



There are 230 stamps which are 3-cent stamps and 5-cent stamps. Altogether they cost 950 cents. How many 3-cent stamps are there?



There are 180 stamps which are 8-cent stamps and 7-cent stamps. Altogether they cost 1330 cents. How many 8-cent stamps are there?



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550    100 130 90 130 90 ( 540 )   110 80 80 100 70 ( 440 )   [[ 980 ]]