When Patience asked her Granddad how old he was, he answered, "I am $$34$$ now and will be $$33$$ on my birthday." She looked confused so he added, "After being $$50$$ for a year I started counting backwards on each birthday. " How old will he actually be on his birthday?　 
Overseas Competition->Knowledge Point->Word Problem Modules->Age Problems->Basic Relationships in Age Problems
When Granddad would have claimed to be $$49$$ he was actually $$51$$, $$48$$ when he was actually $$52$$- in every case his claimed age and his real age have a total of  $$100$$. So this year his age is $$100-33=67$$. 