Elementary school math problem, ask the great god: my brother is 7 years old this year. His age after four years is the same as that of his brother two years ago. How old is my brother this year?
The teacher who gave the questions was not rigorous.
7+4+2= 13
It's 4 o'clock.
Today is
year after year
After ...
... years old
count
My brother is 7 years old.
Brother 13 years old