ANSWER
$63.13
Step-by-step explanation
We have that the cost of the boat is $50.
Each of you and your friends (that is four of you) will pay for a soft drink that cost $2.39 each.
The cost of the soft drinks will therefore be:
4 * 2.39 = $9.56
Adding the cost of the boat, total cost will be:
$9.56 + $50 = $59.56
Now, we have to add a tax of 6%, so we find 6% of total cost:

Finally, add the tax to the cost:
$59.56 + $3.57
= $63.13
You pay a total of $63.13 (including tax)