Carina has 70 ounces of coffee divided into 5- and 10-ounce packages. If she has 2 more 5-ounce packages than 10-ounce packages, how many 10-ounce packages does she have? Select the correct option.
A) 2 B) 3 C) 4 D) 5 E) 6
Lets say 5 and 10 ounce packages be x and y respectively.   Given that, 5x+10y=70 and x=y+2. What is the value of y.   Substituting the x in first equation, 5y+10+10y=70 -&gt;y=60/15.= 
<gadget id="calculator">60/15.</gadget>
<output>4</output>
4   4
<result>C</result>
Carina has 70 ounces of coffee divided into 5- and 10-ounce packages. If she has 2 more 5-ounce packages than 10-ounce packages, how many 10-ounce packages does she have?