The sum of all two digit numbers is :

1. 9810

2. 9045

3. 4509

4. 4905

The sum of A.P. 4, 7, 10, 13, …….. upto 20 terms is :

1. 650

2. 10 × 27

3. 510

4. 1300

The n^th term of an A.P. is 6n + 4. The sum of its first two terms is :

1. 16

2. 20

3. 26

4. none of these

How many terms of the A.P. :

24, 21, 18, ……….. must be taken so that their sum is 78 ?