Is my chemistry book wrong?

Question

what is the ox. number in potassium in this compound K2S

the 2 is on the bottom

since its is in the first column i would say 1 and then multiply it by 2 coz of the 2 potassium atoms but the book says its only 1

so who's right?

Answer 1

K2S IT.S ION COMPOUND.THAT MEANS THERE.S NO BOND BETWEEN K AND K

Answer 2

You're both right.  

In this compound, the oxidation number of potassium is 1, that of sulfur is 2.   Potassium is 1, as you say, because it is in the first column.  

Your only confusion is semantics, interpreting the question.  They don't mean the total oxidation contributed by potassium, they just mean the elemental oxidation number.  This does not depend on the number of potassium atoms.  This is always true when you say "oxidation number".  If you wanted '2' as the answer you would ask for 'the total oxidation of potassium'  or something sounding more like that.