Mathematics
Assertion (A): The sum of first n terms of the A.P. −1, 5, 11, ... is 3n2 − 4n. Reason (R): The sum of first n terms of an A.P. is given by Sn = [2a + (n − 1)d]. 1. A is true, R is false. 2. A is false, R is true. 3. Both A and R are true. 4. Both A and R are false.
Related Questions
If a = 3, n = 8 and Sn = 192, then the common difference of the A.P. is:
4
5
6
7
If the sum of n terms of an arithmetic progression Sn = n2 - n, then the third term of the series is :
2
4
6
9
Assertion (A): The 10th term from the end of the A.P. 17, 14, 11, … −40 is −11.
Reason (R): The nth term of an A.P. is given by tn = a + (n − 1)d.
Both A and R are true, and R is the correct explanation of A.
Both A and R are true, but R is not the correct explanation of A.
A is true, but R is false.
A is false, but R is true.