To begin this problem, you have to know what the reciprocal of a number means. The reciprocal of a number means one over said number. So the reciprocal of 4 would be 1/4 or .25.
From the beginning portion of the word problem, we know that 8*(1/x) equals .5.
Divide both sides by 8 and you get (1/x)=.0625 which is 1/16. So x equals 16.
To make sure we are right, we can plug x back into the equation.
.5=.5 So we are correct.