Let A, B, C,... X,Y,Z be positive numbers such that AC=B,BD=C...XZ=Y.Given that A+B=1988 find max value of Y+Z?
Solution:
Let A = x and C =y
Then B = xy
D=1x
E=1xy
F=1y
G = x
H = xy
I = y
So we see that this is a sequence with a period six. So A = Y and B = Z
Given A+B = 1988, so max value of Y+Z = 1988.