What are the coordinates of point B in the xy-plane above（）

单项选择题If the areas of three of the faces of a rectangular solid are 6，10 and 15，what is the volume of the solid（）

A. 30
B. 90
C. 150
D. 300
E. 450

单项选择题A certain rectangle has perimeter 54．If the ratio of the length of the rectangle to the width is 5 to 4，what is the length of the rectangle（）

A. 30
B. 27
C. 24
D. 18
E. 15