+60 Adam and Justin had a total of 764 marbles. They used some of their marbles to make a marble track each and keep the remaining marbles. Adam had 1/3 as many marbles remaining as Justin after making d their marble tracks. The number of marbles Justin used to make his marble track was 63 more more than what he had left. Justin used 3 times as many marbles is Justin to make his marble track. How many marbles did Adam have at first?
+313 let the number of marbles Adam left be (a)
the number of marbles Justin left will be 3a
the number of marbles Justin used will be 3a+63 which is 3 times to what Adam used
adam used a+21 marbles
adding the used and remaining marbes we get
(a+21)+(3a+63)+a+3a=764
8a+84=764
8a=680
a=85
the number of marbles Adam used are a+21=106
total number of marbles Adam had at first=85+106=191 marbles
