On my sister's 15th birthday, she was 159 cm in height, having grown 6% since the year before. How tall was she the previous year?

Find the total number of ways in which a black square and a white square can be selected from a chessboard such that both the squares lie either in the same row or in the same column.

On a scale of a map 0.6 cm represents 6.6km. If the distance between two points on the map is 80.5 cm , what is the the actual distance between these points?