The first and the last terms of an A.P. are 1 and 11 respectively. If the sum of its terms is 36, then the number of terms is :

1. 6

2. 7

3. 8

4. 9

The sum of first 40 positive integers divisible by 6 is :

1. 2460

2. 3640

3. 4920

4. 4860

The 7th term of an A.P. is 4 and its common difference is −4. The first term of the A.P. is :

1. 32

2. 28

3. 24

4. 36

The sum of first n terms of an A.P. is (4n² + 2n). The nth term of the A.P. is :

1. (6n − 2)

2. (8n − 2)

3. (6n + 2)

4. (8n + 2)