Paul had 30 more marbles than peter. after peter gave paul 15 marbles. paul had twice as many marbles as peter. how many marbles did they have altogether?

I would say that altogether they both had 45 marbles. paul =15 peter =30 
peter gave 15 of his marbles so it would be 30-15=15. paul would then have 30 marbles because 15+15=30 so in the end paul has twice as much marbles. 2 x 15 = 30 . there you go ._. 

(-8,5) bu tun not sure ok