Question 200: what if the teacher asks what is the half of the sum of the brother of my cousin which is 12 and my sister which is 14 after 26 years from my birth... i am 8 years old...???
Found 2 solutions by ichudov, KMST:
Answer by ichudov(507)   (Show Source):
You can put this solution on YOUR website! That's a tough problem for an 8 year old, I am rather impressed. After 26 years, the brother of your cousin will be 12+26 years old, and your sister will be 14 + 26. So, your cousin will be 38 and your sister will be 40 (which is VERY old). The sum of their ages will be 78, half of that sum will be 39.
Answer by KMST(5484)  (Show Source):
You can put this solution on YOUR website! If today is your 8th birthday,
today is exactly 8 years from your birth,
and we can find the answer to your teacher's question.
If today is your 8th birthday,
to get to 26 years from your birth you have to wait exactly  years.
If your birthday was some time before today, you do not have to wait quite as long to get to 26 years after your birth.
Each year that passes everyone gets 1 year older.
The ages of the brother of your cousin and of your sister go up by 1.
The sum of those 2 ages goes up by 2,
but the half of that sum goes up by 1.
The half of that sum is  today,
In exactly 18 years from today, half of that sum will be sum of their ages will be
 ,
but will that be 26 years after your birth?
Only if your 8th birthday is today
If today is not your 8th birthday, we need to know their ages on your 8th birthday.
If the last birthdays of both of them were after your 8th birthday,
they were 11 and 13 on your 8th birthday, and half the sum of their ages was 12.
Then, 18 years after your 8th birthday, when it will be 26 years after your birth, half the sum of their ages will be  .
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