Energy levels A, B, C of a certain atom correspond to increasing

Energy levels A, B, C of a certain atom correspond to increasing values of energy i.e., E_A < E_B < E_C. If λ₁, λ₂, λ₃ are the wavelengths of radiation corresponding to the transitions C to B, B to A and C to A respectively, which of the following relation is correct?

(E₂ - E₁) = hv =	hc
	λ

∴	hc	= (E_C - E_B),	hc	= (E_B - E_A)
	λ₁		λ₂

and	hc	= (E_C - E_A)
	λ₃

Now,
(E_C - E_A) = (E_C - E_B) + (E_B - E_A)

or,	hc	=	hc	+	hc
	λ₃		λ₁		λ₂

or	1	=	1	+	1
	λ₃		λ₁		λ₂

∴	1	=	λ₁ + λ₂
	λ₃		λ₁λ₂

or λ₃ =	λ₁λ₂
	λ₁ + λ₂