Number of people that chose salad = 81 Percentage of people that chose salad over meat dish = 27% Let us assume the number of people on the survey = x Then 27% * x = 81 (27/100) * x = 81 27x = 81 * 100 27x = 8100 x = 8100/27 = 300 So a total of 300 people participated in the survey.I hope the procedure is clear enough for you to understand. Based on this method you can always solve similar types of problems without requiring any kind of help from outside.