If n is an integer and f(n) = f(n – 1) – n, what is the value of f (4)?
(1) f(3) = 14
(2) f(6) = -1
(1) f(3) = 14
(2) f(6) = -1
IMO - D
f(n) = f(n-1)-n ; Find f(4)
stmt1 f(3)=14
so, f(4) = f(4-1)-4
or f(3) -4
or 14-4 =10
stmt1 is suff.
stmt2 f(6)=-1
f(6)=f(6-1)-6=-1
or f(5)-6=-1
or f(5) = 5
so, f(5)=f(5-1)-5
or 5=f(4)-5
or 10=f(4)
stmt2 is suff.
