Paulo is 6 years older than her sister. In 10 years, the sum of their ages be 50. Find their present ages.

Now:

sister's age --- x
Paulo's age --- x+6

10 years from now:
sister's age = x+10
Paulo's age = x+6 + 10 = x+16

x+6 + x+16 = 50

carry on...

To solve this problem, let's assign variables to the ages of Paulo and her sister.

Let P represent Paulo's present age, and S represent her sister's present age.

From the given information, we can deduce two equations:

1. "Paulo is 6 years older than her sister" can be written as: P = S + 6.

2. "In 10 years, the sum of their ages will be 50" can be written as: (P + 10) + (S + 10) = 50.

Let's rewrite equation 2 in terms of P and S:
P + 10 + S + 10 = 50
P + S + 20 = 50

Now, substitute equation 1 into equation 2:
(S + 6) + S + 20 = 50
2S + 26 = 50

Next, isolate the variable S by subtracting 26 from both sides:
2S = 24

Finally, divide both sides of the equation by 2 to solve for S:
S = 12

Now substitute the value of S into equation 1 to find P:
P = 12 + 6
P = 18

Therefore, Paulo's present age is 18, and her sister's present age is 12.