Question

The sum of the first n odd numbers is n^2. The

sum of the first 30 odd numbers is
A)60
B)90
C)300
D)900​

Answer 1

D) 900

Explanation:

So I'm assuming the first part is jsut excess information

What we need to find is the sum fo the first 30 odd numbers -->

to simply calculate this, 1+3+5+7 ... +57+59, we can group the first and last numbers into pairs and so on. this gives us 60 as our first known number and 30/2= 15 pairs. -->

now we multiply 60x15 => 6x15 = 90 --> add 1 zero to the end and you get 900

Hope this helps!