Ron used a combination of 45 cent stamps and 1 cent stamps to mail a package. He used 15 stamps in all. If the total cost for postage was $4.55, how many 1 cent stamps did he use?
2 Answers
5
Explanation:
Let's say
And
Thus :
Thus
Take again the first equation :
He used 5 1c stamps.
There are 10 stamps at 45 cents
There are 15-10=5 stamps at 1 cent
Explanation:
Let the count of 45 cent stamps be
Then the count of 1 cent stamps is
So for total cost we have
but there are 100 cents in 1 dollar so we change the above to
Multiply both sides by 100
There are 10 stamps at 45 cents
There are 15-10=5 stamps at 1 cent
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Check
Total is 455 cents = $4.55