Question

The price to mail a letter at the post office is $0.51 for the first ounce, and $0.20 for each additional ounce. Stephanie paid $1.31 to mail her letter. How much did the letter weigh?A. 7 ounces B.6 ouncesC.4 ounces D.5 ounces

Answer 1

The cost of sending mail is given as $0.51 for the first ounce and then every ounce after that costs $0.20.

For each letter, the cost would be expressed as;

`\begin{gathered} C=0.51+0.20x \\ \text{Where x is the weight in ounces} \\ \text{For Stephanie's letter,} \\ 1.31=0.51+0.20x \\ \text{Subtract 0.51 from both sides} \\ 1.31-0.51=0.51-0.51+0.20x \\ 0.8=0.20x \\ \text{Divide both sides by 0.20} \\ (0.8)/(0.2)=x \\ 4=x \\ \text{Note that she paid \$0.51 for the first ounce} \\ \text{This means she paid for 1 ounce plus another 4 ounces} \\ \text{Stephanie's letter weighs 5 ounces} \end{gathered}`

Therefore, Stephanie's letter weighs 5 ounces.

The correct answer is option D