A, because in order to find the price for each unit you must divide the total price by the number of units bought and 9p=54.90 you would end up dividing both sides by nine which would then get you to find the price of each unit
In order to find the speed at which the boat is traveling, we divide the distance it has traveled by the time elapsed:
2.5/20=0.125 miles/minute
Next, we want to find how long it took for the boat to travel 10 miles. Since it travels 0.125 miles every minute, we just divide:
10/0.125=80
Thus, it took 80 minutes for the boat to reach the bridge
I think it would contain 0.2915 ounces of pure gold in it. sorry if my answer isnt correct