hi, i need help for this question:

$\displaystyle {f}_{n}(x)=n*{\varphi }_{[0,1/n]} $ where $\displaystyle {\varphi}_{[0,1/n]}$ is characterestic function.

1-)what is the value of $\displaystyle \int {f}_{n} d\mu $ over the interval [0,1] ?

2-) if n goes to infinity and $\displaystyle {f}_{n}(x)\to f(x)$ , what is the value of $\displaystyle \int f d\mu $ over the interval [0,1]

thanks for any help.