990  Stamp
How many stamps? 1

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There are 230 stamps which are 3-cent stamps and 8-cent stamps. Altogether they cost 1290 cents. How many 3-cent stamps are there?



There are 180 stamps which are 3-cent stamps and 9-cent stamps. Altogether they cost 1200 cents. How many 3-cent stamps are there?



There are 250 stamps which are 7-cent stamps and 8-cent stamps. Altogether they cost 1860 cents. How many 7-cent stamps are there?



There are 170 stamps which are 5-cent stamps and 8-cent stamps. Altogether they cost 1090 cents. How many 5-cent stamps are there?



There are 250 stamps which are 6-cent stamps and 7-cent stamps. Altogether they cost 1620 cents. How many 6-cent stamps are there?



There are 170 stamps which are 4-cent stamps and 7-cent stamps. Altogether they cost 950 cents. How many 4-cent stamps are there?



There are 240 stamps which are 6-cent stamps and 4-cent stamps. Altogether they cost 1220 cents. How many 6-cent stamps are there?



There are 230 stamps which are 7-cent stamps and 6-cent stamps. Altogether they cost 1510 cents. How many 7-cent stamps are there?



There are 170 stamps which are 7-cent stamps and 4-cent stamps. Altogether they cost 890 cents. How many 7-cent stamps are there?



There are 250 stamps which are 7-cent stamps and 9-cent stamps. Altogether they cost 1950 cents. How many 7-cent stamps are there?



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990    110 70 140 90 130 ( 540 )   80 130 130 70 150 ( 560 )   [[ 1100 ]]