Marley has twice as many oranges as Louis (who has 5 oranges) for a total of 2*5 = <<2*5=10>>10 oranges
He also has thrice as many apples as Samantha (who has 7 apples) for a total of 3*7 = <<3*7=21>>21 apples
Marley has a total of 10+21 = <<10+21=31>>31 fruits
#### 31