Question 1059955
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Sally is 8 years older than john. John is 14 years older than Karen. If the sum of their ages is 90, how old are they?
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<pre>
Let K be the Karen's age.

Then the John's age is (K+14) years, and Sally's age is (K+14)+8 = K + 22 years.

As the condition says, the sum of ages is 90, which gives you an equation

K + (K+14) + (K+22) = 90.

Simplify and solve for K:

3K + 36 = 90,

3K = 90 - 36,

3K = 54,

K = {{{54/3}}} = 18.

<U>Answer</U>. Karen is 18 years old. John is 18+14 = 32 years old. Sally is 32+8 = 40 years old.
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<U>The lesson to learn from this solution</U>:


1.  &nbsp;First choose the major unknown reasonably.


2.  &nbsp;Second, express other unknowns via the major unknown.


3.  &nbsp;Then make an equation.


4.  &nbsp;Then solve the equation.


It is the algorithm.