(a) Simplify : \(625^{\frac{3}{8}} \times 5^{\frac{1}{2}} \div 25\)

(b) Solve the following equations correct to one decimal place. 

(i) \(\tan (\theta + 25)° = 5.145\)

(ii) \(5\cos \theta - 1 = 0\), where \(0° \leq \theta \leq 90°\).