To solve this we must first add up all the values.
3.29+1.28+2.49+1.59=8.65
$8.65 is our total.
Now we find 8% of the total amount. In order to do this we must first find the decimal form of the percent. It's quite simple all we have to do is move the decimal point two spaces forward. We add a 0 in front of the decimal point after that.* (True for all one digit percents)*
8.00%+ 2 spaces forward = 0.08
Then we simply multiply the percent times the total amount.
$8.65*0.08=0.69
We add the last value to the total amount and we have our answer.
$8.65+0.69=$9.34
The total amount benjamin is going to pay is $9.34 (including tax)
Hope this helps and have a great day!