The correct option is B 54
As xyz=90⇒xyz=21×32×51 Let x=2a1×3b1×5c1y=2a2×3b2×5c2z=2a3×3b3×5c3So, a1+a2+a3=1,Total Solutions will be=1+3−1C3−1=3b1+b2+b3=2,Total Solutions will be=2+3−1C3−1=6c1+c2+c3=1Total Solutions will be=1+3−1C3−1=3∴ Total number of solutions are =3×6×3=54.