At what depth below the surface of the earth, acceleration due to gravity g will be half its value 1600km above the surface of the earth?

At what depth below the surface of the earth, acceleration due to grav

1.	At what depth below the surface of the earth, acceleration due to gravity g will be half its value 1600km above the surface of the earth?
Answer» `4.2 xx 10^(6)m` `3.19 xx 10^(6)m` `1.59 xx 10^(6)m` NONE of the above Answer :B