Question 1024837
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Erica wants to buy a bagel that costs $0.70. How many different combinations of nickels and dimes can be used to make $0.70?

 Please help me by telling me how to set up this problem/ how to solve it. 
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<pre>
 0 dimes and 14 nickels,
 1 dime  and 12 nickels, 
 2 dimes and 10 nickels,
 3 dimes and  8 nickels, 
 4 dimes and  6 nickels,
 5 dimes and  4 nickels, 
 6 dimes and  2 nickels,
 7 dimes and  0 nickels.
</pre>

Now, how many lines are there?