Interesting mathematics

Let's say the cost of producing electricity, A, is dependent upon only oil price and other non-fuel factors. And let's call them X and Y respectively. The Energy Market Authority announced that fuel price has come down by 40% and so next quarter, Singaporeans will pay 25% less for electricity. If my primary math serves me well (it better, my son is in primary school!):

X reduces by 40% while Y stays the same, so X + Y = A comes down by 25%

Then 40% of X = 25% of A or simply put, A = 1.6 X

We can now substitute some numbers (for the mathematically-challenged!)

If X = 100, then A = 160 and so Y is 60

Do you believe that operational cost (non-fuel factors) can command 60/160 or 37.5% of the electrical tarrif that you pay? If that were so, power producers will be happy for higher fuel prices as that will mask their operational costs. Now try using X = 60 since it has dropped 40%. Y stays at 60 and A now becomes 120 (25% drop). Now operational cost of 60/120 is a good 50%!

I wonder what was the % when oil price was at $25?