Finding the angle between the hands of a clock at a given time

Use a backward-chaining baseline strategy starting with R's salary . Let R's salary = 100. Q's salary is 20\% lower than R's : 100 - 20 = 80. P's salary is 20\% lower than Q's: 80 - (20\% of 80) = 80 - 16 = 64.

Now, calculate by how much percent R exceeds P: Absolute difference = R - P = 100 - 64 = 36. Required percentage = Difference{P} × 100 = 36/64 × 100.

Simplify the fraction: 9/16 × 100 = 900/16 = 56.25\%.

Answer: (b).