For the reaction

A(g) + B(g) <==> C(g) + D(g)
the equilibrium constant K is defined as

K = Y(sub y) * Y(sub D) / (Y (sub A) * Y(sub b))
where y is the molar fraction of the gas phase of a species

At 620.00 K, the equilibrium constant is 1.100. Suppose the feed to a reactor contains 3.200 mol of A and 1.300 mol of B, no C or D, and reaches equilibrium at 620.00 K.

What is the extent of reaction at equilibrium?

What is the equilibrium mole fraction of each gas?