Given that the sum of the squares of the first seven natural numbers is 140, then their mean is :

1. 20

2. 70

3. 280

4. 980

A bag contains 3 red and 2 blue marbles. A marble is drawn at random. The probability of drawing a black marble is :

1. 0

2. $\dfrac{1}{5}$

3. $\dfrac{2}{5}$

4. $\dfrac{3}{5}$

A mixture of paint is prepared by mixing 2 parts of red pigments with 5 parts of the base. Using the given information in the following table, find the values of a, b and c to get the required mixture of paint.

1. a = 10, b = 10, c = 10

2. a = 5, b = 2, c = 5

3. a = 10, b = 5, c = 10

4. a = 10, b = 5, c = 15

An article which is marked at ₹ 1200 is available at a discount of 20% and the rate of GST is 18%. The amount of SGST is :

1. ₹ 216.00

2. ₹ 172.80

3. ₹ 108.00

4. ₹ 86.40