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Five years ago, Max was twice as old as Bert. A year from now, the sum of their ages would be 30. How old are they now? Show your solution.

User Gudok
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1 Answer

5 votes

Answer:

Bert is 11 years old and Max is 17 years old.

Explanation:

System of Equations

To solve the system of equations, we use two variables x and y. Let's make:

x = current age of Max

y = current age of Bert

x - 5 = age of Max five years ago

y - 5 = age of Bert five years ago

x + 1 = age of Max one year from now

y + 1 = age of Bert one year from now

According to the conditions of the problem, five years ago, Max was twice as old as Bert, thus:

x - 5 = 2(y - 5) [1]

It's also known a year from now, the sum of their ages would be 30:

x + 1 + y + 1 = 30 [2]

Operating and simplifying [1]:

x - 5 = 2y - 10

x = 2y - 5 [3]

Operating and simplifying [2]:

x + y + 2 = 30

x + y = 28 [4]

Substituting [3] in [4]:

(2y - 5) + y = 28

Simplifying:

3y - 5 = 28

3y = 33

y = 33/3 = 11

y = 11

From [3]:

x = 2*11 - 5

x = 22 - 5 = 17

x = 17

Max is 17 years old and Bert is 11 years old

User SystemFun
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