What is 9 is to 2 as x is to 16?

Answer 1

9:2 :: x:16

We note that 16 = 2 x 8

So to bring to equivalence . the 'x' is 9 X 8 = 72

Hence

9:2 :: 72:16

Note the use of colons for 'is to', and 'as'.

Answer 2

x=72