Answer:
25.1%
Explanation:
Let's say m is the true weight and M is the weight of the counterweight.
The original distance between the pans and the center is 25.1 cm / 2 = 12.55 cm. The fulcrum is then moved 1.4 cm towards the counterweight.
Sum of the moments about the fulcrum:
m (12.55 + 1.4) − M (12.55 − 1.4) = 0
13.95 m − 11.15 M = 0
13.95 m = 11.15 M
M / m = 13.95 / 11.15
M / m = 1.251
The true weight is being marked up by 25.1%.