Question

The population of a village increased at the rate of 5%every 10year .what was the population 20 years ago of the village if the present one be 8820

Answer 1

the current population is 8820 and 5% p. 10 year
$8820 \times 4 \div 100 \times 240 \div 12 = 7056$
then
$8820 + 7056 = 15876$
the answer is 15876