A car dealer bought a second – hand car for N250,000 and spent N70,000 refurbishing it. He then sold the car for N400,000. What is the percentage gain?

Simplify $\frac{3({{2}^{n+1}})-4({{2}^{n-1}})}{{{2}^{n+1}}-{{2}^{n}}}$ 

Evaluate ${{5}^{-3{{\log }_{5}}2}}\times {{2}^{2{{\log }_{2}}3}}$

If $\tan \theta =\tfrac{5}{4}$, find ${{\sin }^{2}}\theta -{{\cos }^{2}}\theta$

In the diagram POQ is a diameter of the circle. PQRS. If $\angle PSR={{145}^{o}}$. Find x^o

The gradient of a curve is 2x + 7 and the curve passes through point (2,0). Find the equation of the curve

If log₁₀2 = 0.3010 and log₁₀3 = 0.4771. evaluate log₁₀45

The variance of 3, 2, 3, 6, 2, 4, 4 and 8 is