In a truck of red and green pepper the ratio of red pepper to green pepper is 3:4 if the truck contain 120 green pepper. How many red pepper are there
If the ratio of red pepper to green pepper is 3:4, then the total ratio is 3+4 = 7
Since each segment of the ratio represents an equal number of peppers, then one segment represents 120/4 = <<120/4=30>>30 green peppers
If one segment represents 30 peppers, then 3 segments represent 3*30 = <<3*30=90>>90 red peppers. Answer: \boxed{90}.