Question

Containers are stacked in 20 rows, putting 2 in the top row, 5 in the second row, 8 in the third row, and so on. How many containers are in the pile? help me

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Answer 1

There are 100

Explanation:

Answer 2

Explanation:

The numbers of containers in each row form an arithmetic progression, increasing by 3 each row.

common difference = 3

a₁ = 2

a₂₀ = a₁ + (20-1)d = 2 + 19×3 = 59

Total number = 20 × (a₁ + a₂₀)/2 = 20 × (2 + 59)/2 = 610