11 plus sequencing - don't understand the answer...help...

[stroppyknickers]

ok, am really not getting this. If the sequence is (verbal reasoning):
3, 6, 30, 870 why is the next number 756030????????

Am trying to help (have given in and joined the hysteria) but even with my maths background, I'm still really thick!

32 = 6
65 = 30
3029 = 870
870869 = 756030

it is the last number x by the number before less 1 ie 30*29=870 so 870x869=756030

3 times (3-1) is 6
6 times (6-1) is 30
30 times (30-1) is 870
etc...

so N x N-1 gives you the next number in the sequence

isn't this non verbal reasoning ?

no, this is in my paranoid parents 11 plus fake your way to a top career book under verbal reasoning. not even looked at non verbal reasoning. am so thick. thankyou brainiacs.