Question

suppose your height this year is 10% more than last year and past year your height was 20% more than it was the year before by what percentage has your height increase during the last two years​

Answer 1

20%+10%

=30% is percentage

Answer 2

20%+10%=30%

If this happens then I will become almost 8ft tall as my height is now 190cm(6ft3inches)..