Man with a Million (1954)
As part of a bet, two aristocrats offer a penniless American a loan, without telling him that the amount is 1,000,000 in the form of a single banknote
The Galloping Major (1951)
A syndicate is set up by a horse lover to buy a particular racehorse, but they accidentally buy the wrong horse The horse is useless on the flat, so they decide to enter him as a jumper