Question

At the end of 2020, Helmut will be half as old as his grandmother. The sum of the years they were born in is 3920. How old will Helmut be at the end of 2025?

A) 50 years old
B) 55 years old
C) 60 years old
D) 65 years old

Answer 1

By setting up a system of equations based on the information provided, we find Helmut's age at the end of 2020 to be 40 years old. Adding 5 years to determine his age at the end of 2025, Helmut will be 45 years old, which isn't an option among the provided answers.

Step-by-step explanation:

We're given two pieces of information: Helmut will be half as old as his grandmother at the end of 2020, and the sum of their birth years is 3920. Let's denote Helmut's age at the end of 2020 as H, and his grandmother's age as G. The first piece of information gives us the equation: H = 1/2 G. The second piece of information can be written as: (2020 - H) + (2020 - G) = 3920.

Now we solve this system of equations. First, simplify the second equation: 4040 - H - G = 3920, which results in H + G = 120. Since we know that H is half of G, we can substitute H in the equation to get 1/2 G + G = 120. Solving for G, we find that G = 80 and therefore H = 40.

To find out how old Helmut will be at the end of 2025, we just need to add 5 years to his age at the end of 2020. So, Helmut will be 40 + 5 = 45 years old at the end of 2025, which means the correct answer is not listed in the options provided.