Answer:
Josh's total bill is $ 27.825
Step-by-step explanation:
Given:
The subtotal of the Josh Bill = $21.00
<u>Finding the usual amount Josh gave as Tip To his sever:</u>
Usually josh tips 20% to all servers
So Tip = 20% of his subtotal
=> 
=>
=>
=>4.2
So Josh usually tips $4.2 to his server
<u>Finding the amount Josh gave 25%</u><u> </u><u>as Tip To his sever:</u>
But now he tips 25% which is
=> 25% of 21
=> 
=> 
=> 5.25
Thus the tip amount will be $5.25
So he will be giving (5.25 - 4.2) = $1.05 more than the usual tip
<u>Finding the total bill</u>
The total bill = subtotal+ 7.5% sales tax + 25% tip
=> 21 + 7.5 % of 21 + 25% of 21
=> 
=>
=> 21 +1.575 +5.25
=>27.825