In a flower bed there are 43 rose plants in the first row, 41 in the second, 39 in the third and so on. There are 11 rose plants in the last row. How many rows are there and how many rose plants are there in the bed?

A man saved ₹ 33,000 in 10 months. In each month after the first, he saves ₹ 100 more than he did in the preceding month. How much did he save in the first month?

The nth term from the end of an A.P., whose first term, last term and common difference are a, l and d respectively, is given by:

1. l + (n + 1)d

2. l − (n − 1)d

3. l + (n − 1)d

4. l − (n + 1)d

Sum of n terms of an A.P. whose first term is a and common difference is d, is given by:

1. S_n = $\dfrac{n}{2}[a + (n − 1)d]$

2. S_n = $\dfrac{n}{2}[2a + (n + 1)d]$

3. S_n = $\dfrac{n}{2}[2a − (n − 1)d]$

4. S_n = $\dfrac{n}{2}[2a + (n − 1)d]$