515  Stamp
How many stamps? 1

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There are 220 stamps which are 4-cent stamps and 7-cent stamps. Altogether they cost 1240 cents. How many 4-cent stamps are there?



There are 170 stamps which are 4-cent stamps and 5-cent stamps. Altogether they cost 730 cents. How many 4-cent stamps are there?



There are 220 stamps which are 7-cent stamps and 9-cent stamps. Altogether they cost 1720 cents. How many 7-cent stamps are there?



There are 140 stamps which are 4-cent stamps and 6-cent stamps. Altogether they cost 680 cents. How many 4-cent stamps are there?



There are 200 stamps which are 7-cent stamps and 4-cent stamps. Altogether they cost 1190 cents. How many 7-cent stamps are there?



There are 190 stamps which are 4-cent stamps and 5-cent stamps. Altogether they cost 820 cents. How many 4-cent stamps are there?



There are 250 stamps which are 3-cent stamps and 8-cent stamps. Altogether they cost 1300 cents. How many 3-cent stamps are there?



There are 230 stamps which are 4-cent stamps and 9-cent stamps. Altogether they cost 1420 cents. How many 4-cent stamps are there?



There are 250 stamps which are 8-cent stamps and 6-cent stamps. Altogether they cost 1740 cents. How many 8-cent stamps are there?



There are 210 stamps which are 3-cent stamps and 6-cent stamps. Altogether they cost 870 cents. How many 3-cent stamps are there?



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515    100 120 130 80 130 ( 560 )   130 140 130 120 130 ( 650 )   [[ 1210 ]]