A stack of bricks has 61 bricks in the bottom layer, 58 bricks in the second layer, 55 bricks in the third layer,and so on until there are 10 bricks in the last layer. How many bricks are there all together?
The order of bricks is
This is an arithmetic series with first term
and as sum of the series
Number of bricks is
Number of terms
Hence, the total number of bricks in the stack