30 trees are planted in a straight line at intervals of 5 metres. To water them, the gardener needs to bring water for each tree, separately from a well, which is 10 metres from the first tree in line with the trees. How far will he have to walk in order to water all the trees beginning with the first tree ? Assume that he starts from the well.
30 trees are planted in a straight line at intervals of 5 metres. To water them, the gardener needs to bring water for each tree, separately from a well, which is 10 metres from the first tree in line with the trees. How far will he have to walk in order to water all the trees beginning with the first tree ? Assume that he starts from the well.
The correct option is B 4795 metres
Since the gardener starts from the well
Therefore , Distance covered by gardener for water
to first tree D1 = 0A1 = 10 metre
Therefore , Distance covered by gardener for water
to first tree D1 = 0A1 = 10 metre
Distance covered by gardener for water to second
tree D2 = A10 + 0A2
= 10 + 15 = 25 metr
Distance covered by
gardener for water to third eye D3 = A20 + 0A3
= 15 + 20 =35 metre Distance covered by gardener for water to fourth
tree D4 = A30 + 0A4
Distance covered by gardener for water to all the
trees
D = 10 + 25 + 35 +
45 + ..to 30 terms= 10 + ( 25 + 35 +
45 + to 29 terms)
= 10 + 29 / 2 {
2.25 + (29- 1)10 }
= 10 + 29/2 { 50 +
280}
= 10 + 4785=4795
Since the gardener starts from the well
Therefore , Distance covered by gardener for water
to first tree D1 = 0A1 = 10 metre
Therefore , Distance covered by gardener for water
to first tree D1 = 0A1 = 10 metre
tree D2 = A10 + 0A2
= 10 + 15 = 25 metr
Distance covered by
gardener for water to third eye D3 = A20 + 0A3
= 15 + 20 =35 metre Distance covered by gardener for water to fourth
tree D4 = A30 + 0A4
Distance covered by gardener for water to all thetrees
D = 10 + 25 + 35 +
45 + ..to 30 terms
= 10 + ( 25 + 35 +
45 + to 29 terms)
= 10 + 29 / 2 {
2.25 + (29- 1)10 }
= 10 + 29/2 { 50 +
280}
= 10 + 4785=4795
