b:9:3x2x5=30
[tex] \frac{b}{9 \times 3} \times 2 \times 5 = 30[/tex]
[tex] \frac{b}{27} \times 10 = 30[/tex]
[tex] \frac{b}{27} = 3[/tex]
[tex]b = 3 \times 27 \\ b = 81[/tex]
