With what energy must the radiation be given to image a bone of thickness 5 cm which has covering of skin of thickness of 2 cm on the both sides and the emerging intensity of the X Ray is 200MeV. (impedance for bone = b for skin = s )

With what energy must the radiation be given to image a bone of thickn

1.	With what energy must the radiation be given to image a bone of thickness 5 cm which has covering of skin of thickness of 2 cm on the both sides and the emerging intensity of the X Ray is 200MeV. (impedance for bone = b for skin = s )
A.	2000e<sup>9</sup>
B.	200e<sup>(4s + 5b)</sup>
C.	20/e
D.	2e
Answer» C. 20/e