Answer :

[tex]2,3 \rightarrow 100 \% \\ x = 2,3 - (0,2 * 2,3) \\ \\ x = 1.84m[/tex]


[tex] \\ \\ \frac{2,3}{1,84} = 1,25 \\ Laura's \ jump \ was \ 25\% \ higher[/tex]
Well...
because you need to find 20 percent try looking for a lower number like 10 percent
10 percent is 0.23 and double that is 0.46 which is 20 percent higher and so she Laura jumped 0.46m higher than Lucy!
so Laura jumped 0.46m higher