Question

The population of a town increased by 4% in the first year. The next year, it decreased by 10% and

became 4446. What was the population of the town at the beginning of the first year?
Answer is 4750, but I don't know how solve it. Please, help. :p

Answer 1

Increased of 4% is

100 + 4 = 104%

104/100 = 1.04 (decimal multipiler)

We also know:

Population x 1.04 = first year

Population x 0.9 = 4446 next year

(100% - 10% = 90% & 90/100 is 0.9 d.m)

So, you solve for the start population of next year

Population x 0.9 = 4446 next year

Population x 0.9 = 4446

÷0.9 both sides

Population = 4940

4940 becomes the total population after first year

(100% of the end population of first year)

Thus, we substitute this value into our first year

Population x 1.04 = first year

Population x 1.04 = 4940

÷ 1.04 both sides

Population = 4750 (to start with)

Hope this helps!