Let the number of armour be x.
If the decimal point of a number is shifted to the right by one place, it is equal to the number B, then the number B is 10 times of the number A, that is, 10X.
X+ 10X=24.2
1 1X=24.2
X=2.2
2.2* 10=22
A: The number A is 2.2 and the number B is 22.
The year before last, my father was 24 years older than Xiaoming. Dad is just three times as old as Xiaoming this year. How old are Xiaoming and his father this year?
My father was 24 years older than Xiaoming the year before last, and he is still 24 years older than Xiaoming this year.
If Xiaoming is X years old this year, then Dad is X+22 years old this year.
X+22=3X
2X=22
X= 1 1
1 1*3=33
A: Xiaoming is 1 1 years old and his father is 33 years old.
There are two piles of sand on the construction site. The first pile is 85 tons more than the second pile. After each pile used 30 tons of sand, the first pile was twice as large as the second pile. How many tons are there in two piles of sand?
Let's assume that the first pile of sand used to have x tons, and the second pile used to have X-85 tons.
X-30=(X-85-30)*2
X-30=(X- 1 15)*2
X-30=2X-230
X=200
200-85= 1 15
A: The first pile of sand was originally 200 tons, and the second pile of sand was originally 1 15 tons.