A hemispherical bowl of internal diameter …

Volume of the bowl {tex}= \frac { 2 } { 3 } \pi r ^ { 3 }{/tex}

Volume of liquid in the bowl {tex}= \frac { 2 } { 3 } \pi \times ( 18 ) ^ { 3 } \mathrm { cm } ^ { 3 }{/tex} 

Volume of liquid left after wastage {tex}= \frac { 2 } { 3 } \pi \times ( 18 ) ^ { 3 } \times \frac { 90 } { 100 } \mathrm { cm } ^ { 3 }{/tex}

Volume of one bottle {tex}= \pi r ^ { 2 } h{/tex}

Now ,According to question 

Volume of 72 bottles = volume of liquid after wastage

{tex}\Rightarrow{/tex}{tex}\pi \times ( 3 ) ^ { 2 } \times h \times 72 = \frac { 2 } { 3 } \pi \times ( 18 ) ^ { 3 } \times \frac { 90 } { 100 }{/tex}

{tex}\Rightarrow{/tex}{tex}\pi \times ( 9) \times h \times 72 = \frac { 2 } { 3 } \pi \times ( 18 ) ^ { 3 } \times \frac { 90 } { 100 }{/tex}

{tex}\Rightarrow{/tex}{tex}h = \frac { \frac { 2 } { 3 } \pi \times ( 18 ) ^ { 3 } \times \frac { 90 } { 100 } } { \pi \times ( 9 ) \times 72 }=5.4cm{/tex}

Hence, height of each bottles is 5.4 cm