If d1 is the depth of cutting, d2 is the height of the bank from bed level r2 : 1 and r1 : 1 are the slopes in filling and cutting respectively, the horizontal distance n between the bed and bank, is

If d1 is the depth of cutting, d2 is the height of the bank from bed l

1.	If d1 is the depth of cutting, d2 is the height of the bank from bed level r2 : 1 and r1 : 1 are the slopes in filling and cutting respectively, the horizontal distance n between the bed and bank, is
A.	x = r1 d1
B.	x = r2 d2
C.	x = d1 / r1
D.	x = d2 / r2
Answer» C. x = d1 / r1