Need formula to check multiple conditions and return specific value

OK, I have a user that needs to check for multiple conditions based on the following:
Return value of "5" if value of cell 'n3' is < 80% of cell 'P3' OR cell 'N3" is less than 250
Return value of "4" if value of cell 'n3' is less than 90% or greater than or equal to 80% of cell 'P3' OR cell 'N3" is between 250 and 349
Return value of "3" if value of cell 'n3' is less than 100% or greater than or equal to 90% of cell 'P3' OR cell 'N3" is between 350 and 449
Return value of "2" if value of cell 'n3' is less than 110% or greater than or equal to 100% of cell 'P3'
Return value of "1" if value of cell 'n3' is less than 120% or greater than or equal to 110% of cell 'P3'
Return value of "0" if value of cell 'n3' is 120% or more of cell 'P3'

A co-worker came up with the following nested IF statement, and while it does not error out, the formula returns an incorrect value...

=IF(OR(OR(N3<250,N3=P3),N3<(0.8*P3)),5, IF(OR(OR(N3>=250,N3<=349), OR(N3>=(0.8*P3),N3<(0.9*P3))),4,IF(OR(OR(N3>=350,N3<=449),OR(N3>=(0.9*P3),N3<P3)),3,IF(OR(N3>=P3,N3<(1.1*P3)),2,IF(OR(N3>=(1.1*P3),N3<(1.2*P3)),1,IF(OR(N3>=(1.2*P3)),0,"E"))))))

Can you double check on these three lines.....
Return value of "2" if value of cell 'n3' is 100%< or <= 110% of cell 'P3'
Return value of "1" if value of cell 'n3' is 110%< or <= 120% of cell 'P3'
Return value of "2" if value of cell 'n3' is 120%< or more of cell 'P3'


Last line should be "Return a value of 0?
Other lines, why N3<110% or N3 < 120% of P3? If it's less than 110%, the second part is redundant. What am I missing? I need to get the rules straight before I can put together an IF statement (the order of the IF's will be cruicial) or come up with a different formula.

EDIT: Okay, figured out what you were trying to do. Just that last line is all.

How's this?
=IF(OR(N3<0.8*P3,N3<250),5, IF(OR(AND(N3>0.8*P3,N3<0.9*P3),AND(N3>=250,N3<=349)),4, IF(OR(AND(N3>0.9*P3,N3<1*P3),AND(N3>=350,N3<=449)), 3, IF(AND(N3> 1 * P3, N3< 1.1 * P3), 2, IF(AND(N3> 1.1 *P3, N3<1.2*P3),1, 0)))))
Does that work?

OK, that seems to work quite well. I figured that I needed some sort of 'AND" statement in there, but I was getting cross eyed trying to figure it out.
Many thanks!
BTW, how do I mark this as answered?

Go to original post and click on the EDIT button. Then click on "ADVANCED" and change the prefix. Glad that worked for you.

=IF(G21<90%,6%,IF(G21<=110%,8%,IF(G21<=120%,10%,IF(G21>120%,12%,""))))
Try this, you don't need all the >90<110 because you've already done < 90
and for future reference, for AND, it would be like this
=AND(G21>90%, G21<= 110%)
Hope that helps.