# Mary

Mary is 12 years old, which is 40% of the age of her mother. How many percent of her mother's age will Mary have after the next 12 years?

Result

p =  57.143 %

#### Solution:

$\ \\ 12=0.40 \cdot \ m \ \\ \ \\ 0.4m=12 \ \\ \ \\ m=30 \ \\ \ \\ p=100 \cdot \ \dfrac{ 12+12 }{ m+12 }=100 \cdot \ \dfrac{ 12+12 }{ 30+12 } \doteq \dfrac{ 400 }{ 7 } \doteq 57.1429 \doteq 57.143 \%$

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