Question

In a school, a plantation programme was arranged on the occasion of ‘World Environment Day’, on a ground of triangular shape. The saplings are to be planted as shown in the figure. One plant in the first row, two in the second row, three in the third row and so on. If there are 25 rows, then find the total number of plants to be planted.

Answer 1

Number of saplings planted row-wise are as follows:

1, 2, 3, …

This sequence is an A.P. with

a = 1, d =1, n = 25

\(\therefore\) The total number of plants to be planted is 325.