420  Stamp
How many stamps? 1

Name : _________________

 

refresh

There are 140 stamps which are 3-cent stamps and 7-cent stamps. Altogether they cost 620 cents. How many 3-cent stamps are there?



There are 200 stamps which are 5-cent stamps and 4-cent stamps. Altogether they cost 920 cents. How many 5-cent stamps are there?



There are 210 stamps which are 8-cent stamps and 5-cent stamps. Altogether they cost 1290 cents. How many 8-cent stamps are there?



There are 180 stamps which are 5-cent stamps and 6-cent stamps. Altogether they cost 990 cents. How many 5-cent stamps are there?



There are 190 stamps which are 4-cent stamps and 7-cent stamps. Altogether they cost 910 cents. How many 4-cent stamps are there?



There are 140 stamps which are 6-cent stamps and 9-cent stamps. Altogether they cost 1050 cents. How many 6-cent stamps are there?



There are 180 stamps which are 3-cent stamps and 6-cent stamps. Altogether they cost 720 cents. How many 3-cent stamps are there?



There are 240 stamps which are 3-cent stamps and 7-cent stamps. Altogether they cost 1160 cents. How many 3-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 280 stamps which are 8-cent stamps and 7-cent stamps. Altogether they cost 2110 cents. How many 8-cent stamps are there?



+(         )

 

(         )+

++[[          ]]++

420    90 120 80 90 140 ( 520 )   70 120 130 130 150 ( 600 )   [[ 1120 ]]