Mrs Clarke, whose mother went into labour with her on the journey between Auschwitz and Mauthausen concentration camps, was asked whether she felt the world had changed enough since the Holocaust, and what her view was of modern Germany.
Asked why more non-Jews did not come to the aid of victims of the Nazis, she wrote: "You can't generalise about bystanders. Some didn't help, some did. It's hard to put yourself in their position."
A spokesman for HET said: "This is a really innovative and different way for survivors to engage with young people on their level to make their experiences relevant to them."
"It's amazing that [HET ] are giving people the chance to #askZigi. So glad I got the opportunity to meet him & hear his testimony," said one participant.
