Add 11012,101112 and 1112

If 125\(_x\) = 20\(_{10}\) find x

Evaluate \(\frac{\left(\frac{3}{8}\div\frac{1}{2}+\frac{1}{2}\right)}{\left(\frac{1}{8}\times\frac{2}{3}+\frac{1}{3}\right)}\)

Express 123456 to 3 significant figures

calculate the simple interest on N7,500 for 8 years at 5% per annum.