A jigsaw puzzle has 2 pieces. One of the pieces is shown above. Which one of the given option for the missing piece when assembled will form a rectangle? The piece can be moved. rotated or flipped to assemble with the above piece.

If $$\theta$$ is the angle, in degrees, between the longest diagonal of the cube and any one of the edges of the cube, then cos $$\theta$$ = _______

Six students P, Q, R, S, T and U, with distinct heights, compare their heights and make the following observations:

Observation I : S is taller than R.

Observation II : Q is the shortest of all.

Observation III : U is taller than only one student.

IV : T is taller than S but is not the tallest.

The number of students that are taller than R is the same as the number of students shorter than ________.

The number of student in three classes is in the ratio 3 : 13 : 6. If 18 students are added to each class, the ratio changes to 15 : 35 : 21.

The total number of students in all the three classes in the beginning was :