you're gonna have to translate this to complete sentences
\(\text{let }N \text{ be the total number of kids}\\ R \text{ is the set of kids that bring raincoats}\\ U \text{ is the set of kids that bring umbrellas}\\ |U|=2|R|\\ |U\cap R|=0.08N\)
\(N = |U \cup R| = |U| + |R| - |U \cap R|\\ N = |U|+\dfrac{|U|}{2} - 0.08 N\\ 0.92N = \dfrac 3 2 |U|\\ |U| = \dfrac 2 3 0.92 N = \dfrac{184}{300}N\)
\(|\text{kids that only bring umbrellas}| = |U| - |U\cap R| = \\ \dfrac{184}{300}N - \dfrac{8}{100}N = \dfrac{160}{300}N = \dfrac{8}{15}N\\ \dfrac{8}{15} \approx 53.3\%\)
.