Question

Lana is the oldest of four sisters. Her youngest sister is half her age. The other two sisters are twins $2$ years younger than Lana. When the four sisters' ages are added together, the result is $45$. If the youngest sister is $n$ years old, what is $n$?

Answer 1

n= 7
2n+n+2n-2+2n-2=45
7n-4=45
7n=49
n=7