If d is the economic designed depth of a slab, the thickness of the cement concrete pavement slab at interior, is kept

If d is the economic designed depth of a slab, the thickness of the ce

1.	If d is the economic designed depth of a slab, the thickness of the cement concrete pavement slab at interior, is kept
A.	1.275 d
B.	1.125 d
C.	0.85 d
D.	0.75 d
Answer» D. 0.75 d