Question

over these 3 years, the prize for each unit of gas increased from 5.5 cents to 7.7 cents.
(i) calculate the percentage increase from 5.5 cents to 7.7 cents​

Answer 1

Answer:

And the solution is :

5.5 * X3

=7.7

so my answer was 1.119 but the answer in the mark scheme is 11.9. I asked a friend and she told me that we minus 1.119 by 1 (1.119 - 1)=0.119 then to find the percentage with multiply 0.119*100=11.9. What i don't understand is why we minus by 1