We can set an unknown to find the answer by comparing the value:
Let the cards of Augustin has be y.
As he has 1/4 as many cards Mateo, Mateo has 4 times as much cards as Augustin.
We can then find the car Mateo has:
= 4y
From the statement that Mateo has 1/2 as many cards as Amaro, Amaro has twice as much cards as Mateo:
= 2× (4x)
= 8x
The amoumt they have:
Augustin: y
Mateo:4y
Amaro:8y
As 8y>4y>y
Therefore Amaro has the most cards.
Hope it helps!