Which of the following cannot be determined graphically for a grouped frequency distribution ?

1. Median

2. Mode

3. Quartiles

4. Mean

Volume of a cylinder of height 3 cm is 48π. Radius of the cylinder is :

1. 48 cm

2. 16 cm

3. 4 cm

4. 24 cm

The solution set for the inequation 2x + 4 ≤ 14, x ∈ W is :

1. {1, 2, 3, 4, 5}

2. {0, 1, 2, 3, 4, 5}

3. {1, 2, 3, 4}

4. {0, 1, 2, 3, 4}

Find the value of 'a' if x - a is a factor of the polynomial 3x³ + x² - ax - 81.