Question

Find the missing number of the series. 2, 0, 3, 5, 25, 119, ?

Answer 1

Answer:

721

Step-by-step explanation:

The first element of the series is obtained from the factorial of zero, and then you keep alternating either -1 or +1.

$2=0!+(-1)^0=1+1\\0=1!+(-1)^1=1-1\\3=2!+(-1)^2=2+1\\5=3!+(-1)^3=6-1\\25=4!+(-1)^4=24+1\\119=5!+(-1)^5=120-1$

Therefore, $6!+(-1)6=720+1=721$