A builder is arranging bricks in horizontal rows to form a triangular stack
MATHEMATICS · Multi-part · A Level · Mathematics · Sequences and series · Sequences and series
Problem
A builder is arranging bricks in horizontal rows to form a triangular stack. The bottom row contains 50 bricks, the next row contains 49 bricks, the row above it contains 48 bricks, and so on, with each higher row having one brick fewer than the row just below it. The topmost row ends with exactly 10 bricks.
(i) Determine the total number of rows in the stack.
(ii) Calculate the total number of bricks used to build the entire stack.
(iii) If each brick weighs 2 kg, find the total weight of the stack in kilograms.