The value of $$\,{2^{1/4}}.\,\,{4^{1/8}}.\,{8^{1/16}}...\infty $$ is

Fifth term of a GP is 2, then the product of its 9 terms is

Sum of infinite number of terms of GP is 20 and sum of their square is 100. The common ratio of GP is

$${1^3} - \,\,{2^3} + {3^3} - {4^3} + ... + {9^3} = $$