20 a --- Metric unit of mass 6 letters - I always thought it was a 'kilogram' but it could begin with a g if 'home guard' is right.
Thanks for your help.
I thought of gramme but in all my books and google it comes back as kilogram every time - in the SI system gramme is spelt 'gram' so methinks the compiler has made an error.
Thanks all for your answers. The gram, as we spell it, was a unit of mass in the old CGS system but under the SI system it is the kilogram. So we can assume the compiler has a very old reference book!! Check out this link. http://en.wikipedia.org/wiki/Gram