Which early 1970s Blue Peter Book contained a distance travelled competition?

Question

I'm trying to find out which Blue Peter Book contained a competition in which readers had to estimate how many miles the team totalled on their travels. It is most likely either the Ninth (1972) or Tenth (1973) Book. It is certainly no more than a couple of years either side of this. If anyone still has their old collection and could take a quick look for me, I'd be most grateful.

Answer 1

its 1972.
Defo.