Grade 9 Algebra Question 3
posted by Jab .
TRIANGULAR NUMBERS By arranging
bowling pins in their proper order, a
triangle is created. The table below
shows the number of rows of bowling
pins and the total number of pins in the triangle. The formula:
n * (n+1) / 2
can be used to find t, the total number of items in n rows. How many bowling pins would there be if 10 rows of pins were set up?
Rows 1 2 3 4
Pins 1 3 6 10