assistant on the till is a pair of shoes which you have seen and which you
must have.
The female shopper in front of you has seen them also and is eyeing them
with desire. Both of you have forgotten your purses. It would be rude to
push in front of the first woman if you had no money to pay for the shoes.
The shop assistant remains at the till waiting. Your friend is trying on
another pair of shoes at the back of the shop and sees your dilemma. She
prepares to throw her purse to you.
If she does so, you can catch the purse, then walk round the other shopper
and buy the shoes! At a pinch she could throw the purse ahead of the other
shopper and "whilst it is in flight" you could nip around the other
shopper, catch the purse and buy the shoes!
BUT, you must always remember that until the purse has "actually been
thrown", it would be plain wrong for you to be in front of the other
shopper and you would be OFFSIDE!
EASY!