Question

2/5 of the people at the park are boys, and 1/10 are adults. there are also 15 girls at the park. How many people are at the park.

Answer 1

we can write an equation to solve, I will use the unknow X to represent people at the park

$\frac{2}{5}x+\frac{1}{10}x+15=x$

where x is total people at the park

to solve, group values with x

$\begin{gathered} \frac{2}{5}x+\frac{1}{10}x-x=-15 \\ \\ (\frac{2}{5}+\frac{1}{10}-1)x=-15 \end{gathered}$

simplify

$\begin{gathered} -\frac{1}{2}x=-15 \\ \\ \frac{1}{2}x=15 \\ \\ x=15\times2 \\ x=30 \end{gathered}$

total people at park are 30