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Sean had been thinking about the number problems, and made up this one:
'Fred's father is 30 years older than Fred.
In 20 years, three times Fred's age will be 12 years more than double his father's present
age. How old are Fred and his father at present?'
Sean gave a hint-Take Fred's age to be x years, and make an equation.​

Sagot :

X= fred

y= Fred's father

x+30=y  <=> x=30-y

Final age of father =  (x+30)+12=x+42  

Final age of son =  x+12

x+42=3(x+12)  

x+42=3x+36

2x=42−36=6

x=3

x+30=3+30=33