Answer :
[tex]\dfrac{1}{n}+\dfrac{1}{n+1}=\dfrac{11}{30}\\
30n+30(n+1)=11n(n+1)\\
30n+30n+30=11n^2+11n\\
11n^2-49n-30=0\\
11n^2-55n+6n-30=0\\
11n(n-5)+6(n-5)=0\\
(11n+6)(n-5)=0\\
n=-\dfrac{6}{11} \vee n=5\\\\n=5,n+1=6[/tex]
It's 5 and 6.
It's 5 and 6.