The pattern is n(n+1): 1×2=2, 2×3=6, 3×4=12, 4×5=20, 5×6=30, 6×7=42, 7×8=56.

Since C is between A and D, the arrangement must be A-C-D or D-C-A. B cannot be at the end, so B must be in position 2. Arrangements: A-B-C-D or D-C-B-A, but C must be between A and D. Only A-C-D arrangement works with B in position 2: This doesn't work. Actually: D-C-A-B or A-C-D-B or similar. C is definitely in a middle position.

We cannot determine if roses are red from the given statements. Roses are flowers, but only 'some' flowers are red, not all. Therefore, we cannot make a definitive statement about roses being red.

At 3:00, the minute hand points to 12 and the hour hand points to 3. The angle between them is 90°.

This is the Fibonacci sequence where each number is the sum of the previous two. 8 + 13 = 21.

Volume of box = 5 × 4 × 3 = 60 cubic cm. Volume of each 1 cm cube = 1 cubic cm. Number of cubes = 60.

x : y = 3 : 4 and y : z = 8 : 9. To make y the same in both, multiply first by 2: x : y = 6 : 8. So x : y : z = 6 : 8 : 9.

Work completed per day = 1/12. Work completed in 3 days = 3 × (1/12) = 3/12 = 1/4.

Total balls = 10 + 15 = 25. Probability of red ball = 10/25 = 2/5.

At 3:15, minute hand is at 3 (90°). Hour hand moves 30° per hour + 0.5° per minute = 90° + 7.5° = 97.5°. Angle = 97.5° - 90° = 7.5°