2^x=4^y=8^z......................................................given

2^x=2^(2y)=2^(3z)

x=2y=3z

x.............................................................................(i)

y=x/2.....................................................................(ii)

z=x/3....................................................................(iii)

[1/2x+1/4y+1/4z]..............................................given

{(1/2x)+[1/4(x/2)]+[1/4(x/3)]........................from (i),(ii),(iii)

Simplify

x=7/16

Ans is 7/16