During two years, the population of birds of an island became 7 times more than before. If the first year increase in the population was 40% , what was the percent increase of the second year?

Who asks questions about birds on an island? Anyways, I need help. This is super hard and... I would appreciate it if you would help.

1 answer

i = initial population

(i * 1.4) * x = 7 i

x = 5 ... this means 1 + 400% ... a 400% increase