First, find the tip amount. Convert the percent to a decimal. Move the % sign two places to the left and then make the % sign into a decimal point.
20% = 0.2
Then multiply 0.2 and 36 together.
0.2 * 36 = 7.2
Then add 7.2 to the cost of the dinner.
7.2 + 36 = 43.20
So, the answer is $43.20.