My question is how they got kL1 The table says kl 10 If they

Solution

If you can see the figure as the values of Kl decreases exponentially as the gate is fully open. But there will always be a minor loss hence they have approximated the value as 1 from the graph. And the table gives you r=the values based on various conditions like global fully open or angle fully open. Since any of those conditions are not specified in the question we take the value from graph.