Question

Thu is 5 years older than her brother. The sum of their ages is 51. What are their ages?

A) Thu: 28, Brother: 23
B) Thu: 26, Brother: 21
C) Thu: 30, Brother: 25
D) Thu: 29, Brother: 24

Answer 1

Correct answer is A) Thu: 28, Brother: 23.

To solve this problem, use algebra to set up an equation where x represents the brother's age. Solve for x and determine Thu's age using the equation x + 5.

Step-by-step explanation:

We can solve this problem using algebra. Let's assume that the brother's age is x. Thu's age is then x + 5 because she is 5 years older than her brother. The sum of their ages is 51, so we can write the equation x + (x + 5) = 51.

Combining like terms, we have 2x + 5 = 51. Subtracting 5 from both sides, we get 2x = 46. Dividing by 2, we find x = 23. Therefore, the brother's age is 23 and Thu's age is 23 + 5 = 28.

So the correct answer is A) Thu: 28, Brother: 23.