Number of cards they have 160 in the end.
Step-by-step explanation:
Given,
The ratio of cards David and Sam has = 4:5
Again,
David collected an additional 50% of cards.
Sam doubled his number of cards.
Sam now has 40 more cards than David
To find total number of cards they have.
Let,
David has 4x cards
Sam has 5x cards
Again,
Number of cards David has = 4x × = 6x
Number of cards Sam has = 5x×2 = 10x
According to the problem,
10x = 6x+40
or, 10x-6x = 40
or, 4x = 40
or, x = 10
Altogether they have = 6x+10x = 16x
= 16×10 = 160
Hence,
Number of cards they have 160 in the end.