Step-by-step explanation:
(a) Let x% of 40 = 19
Therefore, \(\frac{x}{100} \times 40 = 19\)
\(\frac{4x}{10} = 19\)
x = \(\frac{190}{4}\)
x = 47.5
Thus, 47.5% of 40 = 19.
(b) It is given that \(\frac{5}{x} = \frac{4}{8}\)
\(x = \frac{5 \times 8}{4}\)
x = 10
Thus, we can conclude that the value of x = 10.
