At 400 nm, A = 0.030 = e cl = 2000 (c) 1

c = 0.030/2000 = 1.5X10^-5 and c is constant.

At 600 nm and l = 50.0 cm; A = e cl = 3000(1.5X10^-5)(50.0cm) = 2.25

A = 2.25 = log(I₀/I)

I₀/I = antilog 2.25 = 178

%T = (I/I₀)100 = 100/178 = 0.56%