Answer:
1). 1 decade
2). 2 decades
Step-by-step explanation:
Number of years in decade = 10 years
1). When we are calculating the population of Florida between 1840 to 1850,
Number of years between 1850 and 1840 = 1850 - 1840
                                   = 10 years
So number of decades between 1840 and 1850 = [tex]\frac{10}{10}[/tex] = 1 decade
2). Number of years between 1840 and 1860 = 1860 - 1840
                                      = 20 years
Therefore, number of decades between this gap = [tex]\frac{20}{10}=2[/tex] decades