Update examples/step-68/doc/intro.dox

Co-authored-by: Peter Munch <peterrmuench@gmail.com>

diff --git a/examples/step-68/doc/intro.dox b/examples/step-68/doc/intro.dox
index cfca2e80b9a3ade0c6cbecbda6395c7c3cfdefe3..9314c3782a8882c50178c8607dab98f89adecfd4 100644 (file)
--- a/examples/step-68/doc/intro.dox
+++ b/examples/step-68/doc/intro.dox
@@ -23,7 +23,7 @@ Particles play an important part in numerical models for a large
  or they can even be used to simulate the motion of granular matter, as is
  the case with the Discrete Element Method (DEM) (Blais et al. 2019). In the case
  of DEM, the resulting model is not related to the finite element method anymore,
- but just leads to a serie of ordinary differential equation which describes
+ but just leads to a system of ordinary differential equation which describes
  the motion of the particles and the dynamic of their collisions. All of
  these models can be built using deal.II particle handling capabilities.