A. B and C are boxes with marbles in the ratio 2 : 3 : 4. The total number of marbles in the boxes is 360. The above ratio can be changed to 3 : 8 : 7 by which of the following?
(i) By transferring 20 marbles from A to B and 20 marbles from C 10 B.
(ii) By u.msferring 20 marbles from A to Band 10 marbles from C 10 B.
(iii) By transfen-ing 40 marbles from A to Band 20 marbles from C to B.
(iv) By transferring 30 marbles from A to B and 30 marbles from C to B.