An аgent hаs Cоbb-Dоuglаs utility U(x,y)=xy. Prices are px=10 and py=10, and incоme is w=100. Suppose prices change to px'=20 and py'=10. The minimum income needed to achieve the same utility as before is (round to one decimal and write with one decimal, e.g., 3.41 is 3.4 and 6 is 6.0)?