The reciprocal of a whole number is a fraction with the whole number as the denominator.
Set up the equation:
10 * 1/x = 5 * 1/3
Simplify:
10/x = 5/3
Multiply both sides by 3:
30/x = 5
multiply both sides by x:
30 = 5x
Divide both sides by 5:
x = 6
Answer: 6