900  Stamp
How many stamps? 1

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There are 250 stamps which are 7-cent stamps and 9-cent stamps. Altogether they cost 1970 cents. How many 7-cent stamps are there?



There are 190 stamps which are 7-cent stamps and 6-cent stamps. Altogether they cost 1250 cents. How many 7-cent stamps are there?



There are 220 stamps which are 4-cent stamps and 3-cent stamps. Altogether they cost 780 cents. How many 4-cent stamps are there?



There are 220 stamps which are 3-cent stamps and 5-cent stamps. Altogether they cost 860 cents. How many 3-cent stamps are there?



There are 210 stamps which are 8-cent stamps and 6-cent stamps. Altogether they cost 1520 cents. How many 8-cent stamps are there?



There are 270 stamps which are 3-cent stamps and 4-cent stamps. Altogether they cost 940 cents. How many 3-cent stamps are there?



There are 190 stamps which are 6-cent stamps and 4-cent stamps. Altogether they cost 920 cents. How many 6-cent stamps are there?



There are 180 stamps which are 6-cent stamps and 7-cent stamps. Altogether they cost 1140 cents. How many 6-cent stamps are there?



There are 220 stamps which are 7-cent stamps and 9-cent stamps. Altogether they cost 1740 cents. How many 7-cent stamps are there?



There are 280 stamps which are 8-cent stamps and 9-cent stamps. Altogether they cost 2370 cents. How many 8-cent stamps are there?



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900    140 110 120 120 130 ( 620 )   140 80 120 120 150 ( 610 )   [[ 1230 ]]