The quickest and easiest way to understand any currency exchange is to run a search in Google. In your case a search of "20 pounds in dollars" will bring you the result you want.
20 British Pounds = 32.85 US Dollar - Feb 3rd, 2014
Fourty dollars is about 20 pounds
32.78 dollars
12.4278
$20 AUD is £12.08
Approx £20.
2005
31.4380 US dollars
around 20 to 30 austrailan dollars.
$20 CAD is £12.43
250 million British pounds = 387.92500 million U.S. dollars
$20 is £16.48.
100 pounds