initial population of a town is 3400 and it grows with a doubling time of 10 years what will the population be in 8 years

So in 10 years, the population will double.

8 years is just before doubling to 6800.

If you consider 10 years to be 100% of the doubling time, 8 years is 80%.

And 80 as a decimal is 80/100 = 0.8

So the answer is 0.8 * 6800, simplify.