Matt had a full jar of marbles. he gave kayla 3/4 of the marbles. then kayla returned 1/3 of a jar's worth of marbles to the jar. how much of the jar is full of marbles?

7/12 jar is full of marbles

Step-by-step explanation:

Matt had full Jar  of Marbles =  1

After giving 3/4 to Kayla , jar has marbles =

Kayla returned  =   1/3 of Jar

Now jar has marbles =     1/3+ 1/4

                                 =   4/12 + 3/12     [ making denominator same]

                                 =  7/12