1 When the son is 9 years old, the father's age is exactly four times that of his son. Because my father is 36 years old.
1 235 yuan
Twenty-five thousand yuan
Articles 3, 47 and 53
415km
Grandpa won six sets and grandson won two sets.
6 More than three hours and twenty minutes (24/7)
7 10 hectare
33 people got married and 84 people died.
9 lost money
10 80 km
11255m
12 20 ,24, 44, 1 1
1 a= 7