NIMCET 2012 Question Paper with solutions

Let f (x) = $3{\mathit{x}}^5$ + 15 x - 8 = 0
For positive roots, f (x) = 1
For negative roots,
f (-x) = $-3{\mathit{x}}^5-15\mathit{x}-8$ = 0
∴ Real roots = Number of positive roots- Number of negative roots = 1-0 = 1