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

check your formula for row 4 , (n=4)

number of pins = 4(5)/2 = 10
checks out with your chart

so if n=10
number of pins = 10(11)/2 = 55

Thanks Reiny!

To find the total number of bowling pins in 10 rows, we can use the formula given:

t = n * (n + 1) / 2

Here, t represents the total number of pins and n represents the number of rows.

Substituting the value of n as 10 into the formula, we get:

t = 10 * (10 + 1) / 2

Simplifying the expression inside the brackets, we have:

t = 10 * 11 / 2

Now, we can perform the multiplication:

t = 110 / 2

And finally, we can divide to get the total number of bowling pins:

t = 55

Therefore, there would be a total of 55 bowling pins if 10 rows of pins were set up.