Find the missing term in the series: $7, 4, 5, 9, ?, 52.5, 160.5$

$980, 484, 236, 112, 50, ?, 3.5$

Find the odd number in the given sequence: $32, 34, 37, 46, 62, 87, 123$.

Find the missing term in the series: $4.5, 16, ?, 33, 38.5, 42, 43.5$

$8, 9, 20, 63, 256, 1285, ?$

If $A = \left(\frac{1}{0.4}\right) + \left(\frac{1}{0.04}\right) + \left(\frac{1}{0.004}\right) + \dots$ up to $8$ terms,then what is the value of $A$ (in $.5$)?