Answer: The cost of postage for a letter weighing 3 ounces= 56 cents.
Explanation:
The cost of postage for the first ounce =22 cents
The cost of postage for each additional ounce = 17 cents
Now, the cost of postage for a letter weighing 3 ounces=
![22\ cents+2(17)\ cents](https://img.qammunity.org/2019/formulas/mathematics/middle-school/fxjyspusvn50lithnxlqa4nze3lx6zb7zt.png)
Therefore, the cost of postage for a letter weighing 3 ounces=
![22\ cents+34\ cents](https://img.qammunity.org/2019/formulas/mathematics/middle-school/6fcd38wej0a1tcz0he970qkcsd0mw7pvaw.png)
Hence, the cost of postage for a letter weighing 3 ounces= 56 cents.