Ali        (3/5)(c+b+d)
Cindy         c=(1/2)(b+d)
Ben           b=(1/3)d
Daniel        d

(3/5)(c+b+d)=d+39

Let x be the number of marbles Ben had.


Then from (3), Daniel had 3x marbles,
     and Ben and Daniel had together x+3x = 4x marbles.


Then from (2), Cindy had 0.5*(4x) = 2x marbles, 
     and 3 friends, Ben, Cindy and Daniel, had together 4x+2x = 6x marbles.


Then from (1), Ali had 0.6*(6x) = 3.6x marbles.


We are given in (4), that 

    3.6x - 3x = 39.


It gives us

    0.6x = 39,  x =  = 65.


Hence, altogether they had  6x+3.6x = 9.6x = 9.6*65 = 624 marbles.    ANSWER

Hi
Ali had 60% of the total number of marbles  his other 3 friends had. Cindy had 50% of the total number Ben and Daniel had. The number Ben had was 1/3  the number daniel had. If ali had 39 more marbles than daniel, how many did they have altogether. Thanks

Let number Ben has, be B
Since Ben has  Daniel's amount, Daniel then has thrice Ben's, or 3B
Cindy has  of Ben and Daniel's total, and with Ben and Daniel having 4B (B + 3B), Cindy then has: 

Finally, it's said that Ali has 60% of all 3's total, or .6(Ben's + Cindy's + Daniel's), or .6(B + 2B + 3B) = .6(6B) = 3.6B
It's also said that Ali has 39 more than Daniel, or 3B + 39 
                   Therefore, we get: 3.6B = 3B + 39
                                 3.6B - 3B = 39
                                       .6B = 39
                   Number Ben has, or 

                             Total: A  +  B +  C  +  D, or
                                  3.6B +  B + 2B  + 3B = 9.6B 

     Total number of marbles:

                                             OR

                 OR  

                                                        You think you can add them up?