Question

What is the 100th odd number

Answer 1

Well,

To find what the hundreth odd number is, use this formula: (n * 2 ) - 1

(n * 2 ) - 1

n = 100

(100 * 2 ) - 1

200 - 1

= 199.

The hundreth (100th) odd number is 199.

Answer 2

$First\ odd\ number\ is:1\\second\ odd\ number\ is:3\\difference\ is:3-1=2\\\\it's\ an\ arithmetic\ sequence\ where\ a_1=1\ and\ d=2\\\\n(th)\ number\ of\ this\ seqence\ we\ calculate\\from\ formula:a_n=a_1+(n-1)d\\\\formula\ from\ yours\ example:\\a_n=1+(n-1)\cdot 2=1+2n-2=2n-1\\\\so...\ conclusion:\\\\a_{100}=2(100)-1=200-1=\boxed{199}\leftarrow answer$