Loss of working time has decreased by four times. By what percentage have these losses decreased?

Let’s designate the working time before its reduction as (X), then after its reduction by four times: (x / 4).
To find the difference in percentage, let’s make the proportion:
X – 100%
(X / 4) – y%
Let’s compose and solve the equation: y = ((x / 4) * 100) / x
in the fraction in the denominator, we reduce 100 and 4, we get:
y = (25x) / x
x in the numerator and x in the denominator cancel out, we get:
y = 25
Answer: the loss of time has decreased by 25%.