Problem #878

 878 Chandra pays an on-line service provider a fixed monthly fee plus an hourly charge for connect time. Her December bill was $12.48$, but in January her bill was $17.54$ because she used twice as much connect time as in December. What is the fixed monthly fee? $\mathrm{(A)} 2.53 \qquad\mathrm{(B)} 5.06 \qquad\mathrm{(C)} 6.24 \qquad\mathrm{(D)} 7.42 \qquad\mathrm{(E)} 8.77$ This problem is copyrighted by the American Mathematics Competitions.
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• Reduce fractions to lowest terms and enter in the form 7/9.
• Numbers involving pi should be written as 7pi or 7pi/3 as appropriate.
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