Solution:Let initial price is P1, initial quantity is Q1, the final price is P2, final quantity is Q2Here, P1 = Rs. 50, P2 = Rs. 75, Q1 = 100 and Q2 = 50 On putting values, we get,
Price elasticity of demand
= (-) (Q2-Q1) × P1/(P2-P1) × Q1
= (-) {(50-100) × 50/(75-50)} × 100 = 1
Therefore, the correct option is (d).