A gardener is making a planting in the shape of a trapezoid. It will have 41 plants in the front row, 37 in the second row, 33 in the third row, and so on. If the pattern is consistent, how many plants will there be in the last row? How many plants are there altogether?

Question

A gardener is making a planting in the shape of a trapezoid. It will have 41 plants in the front​ row, 37 in the second​ row, 33 in the third​ row, and so on. If the pattern is​ consistent, how many plants will there be in the last​ row? How many plants are there​ altogether?

Thank you!

Steve · Answer

The nth row, Rn = 41-4(n-1) = 45-4n So, there are 11 rows, since 45-48 < 0 You have an AP with a = 41 d = -4 S11 = 11/2 (2*41 + 10(-4)) = 231

A gardener is making a planting in the shape of a trapezoid. It will have 41 plants in the front​ row, 37 in the second​ row, 33 in the third​ row, and so on. If the pattern is​ consistent, how many plants will there be in the last​ row? How many plants are there​ altogether?

A gardener is making a planting in the shape of a trapezoid. It will have 41 plants in the front row, 37 in the second row, 33 in the third row, and so on. If the pattern is consistent, how many plants will there be in the last row? How many plants are there altogether?