There are three boxes – P, Q and R, containing marbles in the ratio 1 : 2 : 3. Total number of marbles is 60. The above ratio can be changed to 3 : 4 : 5 by transferring :

1. 2 marbles from P to Q and 1 from R to Q

2. 3 marbles from Q to R

3. 4 marbles from R to Q

4. 5 marbles from R to P

If x² + 4y² = 4xy, then x : y is :

1. 1 : 1

2. 1 : 2

3. 1 : 4

4. 2 : 1

If, A : B = 7 : 9 and B : C = 5 : 4, then A : B : C is:

1. 7 : 45 : 36

2. 28 : 36 : 35

3. 35 : 45 : 36

4. none of these