25 trees are planted in a straight line 5 metres apart from each other. To water

25 trees are planted in a straight line 5 metres apart from each other. To water them the gardener must bring water for each tree separately from a well 10 metres from the first tree in line with the trees. How far will he move in order to water all the trees beginning with the first if he starts from the well ?

2) An AP consist of 31 terms if its 16th term is m, then sum of all the terms of this AP is

3) A.P whose nth term is 2n-1 is

4) 2,4,6,8,10,12,… is

5) The sum of the first ten terms of an AP is four times the sum of the first five terms, then the ratio of the first term to the common difference is