#### Explanation:

So let convert 15% to a decimal value before we start solving anything. So you simply divide 15 over 100 like this: $\frac{15}{100}$ which gives you 0.15.

So to find out how much tip they are giving, you multiply 0.15 by 42.00. Here is what I am saying shown below:

0.15*42.00=?

So let compute that by plugging that into the calculator which we get $6.3. Now, we can add that back to the meal cost as shown below: 42.00+6.30=? Our final answer is: $48.3