This is what the statement means in mathematical form.
Let: y = age of Diana
x = age of Antonio
x - 4 = 3 (y-4)
x + 10 = 2 (y + 10)
x -4 = 3y - 12
- x+10 = 2y + 20
0 -14 = y - 32
-14 = y - 32
-14 + 32 = y
18 = y
x + 10 = 2y + 20
x = 2y + 20 -10
x = 2y + 10
x = 2(18) + 10
x = 36 + 10
x = 46
Antonio's present age is 46 years old.
Diana's present age is 18 years old.
Check:
4 years ago, Antonio's age is 3 times the age of Diana.
46 - 4 = 18 - 4
42 = 14
42 is 3 times 14, Correct.
In 10 years, Antonio's age will be twice the age of Diana.
46 + 10 = 18 + 10
56 = 28
56 is twice of 28, Correct.