Question

When the positive even integer n is increased by 50% of itself !the result is between 10&20 . Find n

Answer 1

`n+50\%n=n+0.5n=1.5n\\\\1.5n\in (10,20)\ \ \ \Leftrightarrow\ \ \ 20>1.5n>10\ /\cdot2\ \ \ \Leftrightarrow\ \ \ 40>3n>20\ /:3\\\\(40)/(3) >n>(20)/(3) \ \ \ \Leftrightarrow\ \ \ 13(1)/(3) >n>6(2)/(3) \ \ \ and\ \ \ n\in I\\\\Ans.\ n\in\{7,8,9,10,11,12,13\}`