Cynthia is three years old than Dina. The sum of their ages is 31. Find their ages.
x + (3+x) = 31
3 + 2x = 31
2x = 28
x = 14
Dina must be 14.
To find the ages of Cynthia and Dina, we can use algebra. Let's assume that Dina's age is represented by the variable "x."
According to the given information, Cynthia is three years older than Dina, so her age can be represented by "x + 3."
The sum of their ages is 31, which can be represented as the equation:
x + (x + 3) = 31
Now, we can solve this equation to find the value of x, which would give us Dina's age.
Combining like terms:
2x + 3 = 31
Subtracting 3 from both sides:
2x = 28
Dividing both sides by 2:
x = 14
So, Dina's age (x) is 14.
By substituting this value back into the equation for Cynthia's age (x + 3):
14 + 3 = 17
Therefore, Dina is 14 years old, and Cynthia is 17 years old.