### Math Notes

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#### Algebra Solutions

##### Topics || Problems

At present John's age is 30% of his father's age. Twenty years from now, Jon's age will by 58% of his father's age. How old are they? Solution:
 Age at Present Age 20 years from the present Father F F+20 Son(John) J J+20 Relationship $$J = 0.30 F$$ J+20 = 0.58 (F+20)

$$J+20 = 0.58F + 11.6$$

$$0.30F+20 = 0.58F + 11.6$$

$$F = 30$$

$$J = 0.30(30) = 9$$

Thus, the father's age at present is 30 years old and the son (John) is 9 years old.