Respuesta :
1 x 20
2 x 10
4 x 5 (these go the other way round as well, like 10 x 2, etc)
all factors of 20 = 1,2,4,5,10,20
hope this helps!
The factors of 20 are the numbers, which produce the result as 20 when a pair of factors are multiplied together. These factors are 1,2,4,5,10 and 20.