Correct Answer - Option 4 : 95%
Given:
Efficiency of A = 20% more than B
Efficiency of B = 30% more than C
Efficiency of C = 25% more than D
Calculations:
Let efficiency of A, B, C, D.
C = D + (25% of D)
⇒ D + 0.25D
⇒ 1.25D
B = C + (30% of C)
⇒ C + 0.30C
⇒ 1.30C
⇒ 1.30 × 1.25D
⇒ 1.625D
A = B + (20% of B)
⇒ B + 0.20B
⇒ 1.20B
⇒ 1.20 × 1.625D
⇒ 1.95D
Percentage difference = {(1.95D - D)/D} × 100
⇒ (0.95D/D) × 100
⇒ 95%
∴ Efficiency of A is 95% more than efficiency of D.