Oh its simple, is this for morris?

Ali + Colin = 52 marbles
Ali + Baba = 44 marbles

We know
(Ali) : (Colin+Baba)
5 : 14

There fore, now lets try all the possible combinations.
Case 1:
-------
Ali has 5 marbles
so Colin has 52-5=47 marbles
so baba has 44-5 marbles=39 marbles
So the ratio is ----> 5 : (47+39) -------> 5 : 86 which cannot be correct because it said its 5:14

Case 2:
-------
Ali has 10marbles
so Colin has 52-10=42 marbles
so baba has 44-10 marbles=34 marbles
So the ratio is ----> 10 : (42+34) -------> 10 : 76 ----> 5:38 which cannot be correct because it said its 5:14

Case 3:
-------
Ali has 15 marbles
so Colin has 52-15=37 marbles
so baba has 44-15 marbles=29 marbles
So the ratio is ----> 15 : (37+29) -------> 15 : 66 ---> 5:33 which cannot be correct because it said its 5:14

Case 4:
-------
Ali has 20 marbles
so Colin has 52-20=32 marbles
so baba has 44-20 marbles=24 marbles
So the ratio is ----> 20 : (32+24) -------> 20 : 56 --> 5:14 tadaa.. the answer