length=22in,width=20in, height=1in
Total Surface are of a table = 2(length * width) + 2(width * height) + 2(height * length)
= 2(22*20) + 2(20*1) + 2(1*22) = 880 + 40 +44= 964 square inches
the surface area of underside table is legth * width = 22* 20 = 440
the underside remains unpainted, so we subtract 440 from total surface
964 - 440 = 524 square inches
440 square inches will remain unpainted
524 square inches will be painted