?
Puzzle 29
How much soil is there …
… in a circular hole 2 metres deep and 1 metre across?
?
Puzzle 30
Which is heaviest …
a pound of feathers
a pound of wood
a pound of steel
How much soil is there …
… in a circular hole 2 metres deep and 1 metre across?
Which is heaviest …
a pound of feathers
a pound of wood
a pound of steel