Read the directions carefully and answer the following questions. There are five colours Black, Green, Grey, Red and Yellow kept in five boxes. Each box is assigned a number from 1 to 5, where the bottommost box is numbered as 1 the box above it as number 2 and so on. Grey is kept exactly in the middle. Black is kept three boxes above Yellow. Red is kept below Green but above Yellow. How many boxes are kept below Black?