Convert 89\(_{10}\) to a number in base two.

A stick of length 1.75m was measured by a boy as 1.80m. Find the percentage error in his measurement

The nth term of a sequence is given by (-1)\(^{n-2}\) x 2\(^{n-1}\). Find the sum of the second and third terms.

Simplify: \(\frac{4^{-\frac{1}{2}} \times 16^{\frac{3}{4}}}{4^{\frac{1}{2}}}\)

Simplify: \(\frac{\log \sqrt{27}}{\log {81}}\)