Given :-
[tex] \\ \\ [/tex]
To find:-
[tex] \\ \\ [/tex]
First let's find increase in price :-
[tex] \\ [/tex]
[tex] \boxed{ \rm increase\% = \frac{increase}{original \: price} \times 100 }[/tex]
[tex] \\ \\ [/tex]
So:-
[tex] \\ [/tex]
[tex] \dashrightarrow \rm increase\% = \sf \dfrac{increase}{original \: price} \times 100 \\ [/tex]
[tex] \\ \\ [/tex]
[tex] \dashrightarrow \rm increase\% = \sf \dfrac{6}{30} \times 100 \\ [/tex]
[tex] \\ \\ [/tex]
[tex] \dashrightarrow \rm increase\% = \sf \dfrac{6}{3\cancel0} \times 10\cancel0 \\ [/tex]
[tex] \\ \\ [/tex]
[tex] \dashrightarrow \rm increase\% = \sf \dfrac{6}{3} \times 10 \\ [/tex]
[tex] \\ \\ [/tex]
[tex] \dashrightarrow \rm increase\% = \sf \cancel\dfrac{6}{3} \times 10 \\ [/tex]
[tex] \\ \\ [/tex]
[tex] \dashrightarrow \rm increase\% = \sf 2\times 10 \\ [/tex]
[tex] \\ \\ [/tex]
[tex] \dashrightarrow \bf increase\% = 20\%[/tex]