CareerCup

-3 x -2 = 6
6 x -3 = -18
-18 x -4 = 72
72 x -5 = -360
-360 x -6 = 2160

so next number in the series is 2160.

-3+3*3=6
6-6*4=-18
-18+18*5=72
72-72*6=-360
-360+360*7=2160

Initial number is -3.
3 * 2 = 6
6 * 3 = 18
18 * 4 = 72
72 * 5 = 360

So the next number will be 360 * 6 = 2160..
Assign '-' sign to every alternate number in the seies. So the answer is 2160.

2160

-360 * 6

-360 * -6 = 2160

This is to determine sequence, a topic from discrete math.

We seek a_n, where
a_1 = -3 = -1 * 3
a_2 = 6 = 1 * 3 * 2
a_3 = -18 = -1 * 6 * 3
a_4 = 72 = 1 * 18 * 4
a_5 = -360 = -1 * 72 * 5

By inspection, the sequence is produced by
with initial condition n =1:
a_1 = -3
and subsequent sequence given by
a_n = (-1)**(n-1) * a_(n-1) * n for n > 2


Implemented in python:
{
import math
def a(n):
init = -3
pre = init
print pre

i = 2
while i < n + 1:
answer = (-1)**(i) * abs(pre) * i
print answer
pre = answer
i = i + 1
}

>>> a(6)
-3
6
-18
72
-360
2160

Of all the stupid questions, these type of questions are EPIC.