Three brothers share some cash.
The ratio of Mark's and David's share is 1:2.
The ratio of David's to paul's share is 1:2.
What is the ratio of Mark's and Paul's share?

Question

Three brothers share some cash. 
The ratio of Mark's and David's share is 1:2.
The ratio of David's to paul's share is 1:2. 
What is the ratio of Mark's and Paul's share?

anonymous · Answer

1:4

anonymous · Answer

How?

anonymous · Answer

davids share is twice mark's
and paul's is twice davids 
so pauls must be 4 times marks

anonymous · Answer

suppose mark has $2 then david must have 4 dollars
davids : pauls is 1:2 and david has 4 dollars
so paul must have 4*2 = 8 dollars
so mark: paul = 2:8  which is same as 1:4

anonymous · Answer

I got it, but what you just posted confused me.

anonymous · Answer

oh! - it was supposed to help!
its just a possible illustration of the set-up