If decreasing 111 by x% gives the same result as increasing 37 by x%, then x% of 570 is what percentage more than (x -10)% of 1140 ? (correct to nearest integer)
Answer & explanation
Correct answer: option 3
let x% = f
According to question ,
111 (1 - f) = 37 (1 + f)
\(\frac{1 - f}{1 + f}\) = \(\frac{1}{3}\)
\(\frac{1}{f}\) = \(\frac{4}{2}\) = \(\frac{2}{1}\)
x% = f = \(\frac{1}{2}\) × 100 = 50%
Now →
\(\frac{570 × 50}{1140 × (50 - 10)%}\) = \(\frac{570 × 50}{1140 × 40}\)
= \(\frac{5}{8}\)
Required percentage = \(\frac{8-5}{8}\) = \(\frac{5}{8}\)
= 37.5%