Basic maths question?

[pureklas]

If I have a horse at 7/1 and another at 3/1 and i want to do an each way double. The bookmaker pays up to 4 places for the each way (1/4 the odds). How do I calculate how much I will get on a £100 bet (£50 each way). Can someone break it down for me into basic maths?

[Copernicus]

Try this in the sports betting forum, and you still might not find someone who understands your terminology.