In 2010, the continent of South America had a population of 395, 280, 204 Which of the following is the closest estimate of this number? O 3 x 10^8
O 4 x 10^7
O 4 x 10^8
O 4x 10^9

Given:

The population of continent of South America in 2010 is 395, 280, 204.

To find:

The closest estimate of this number.

Solution:

We have,

The approximate value of this number is

The scientific form of this value is

Therefore, the correct option is C.

area of part 1:

a1=base*height/2=(8+2)*(8-2-2-1)/2=10*3/2=15 ft^2

area of part 2:

a2=length*width=(8+2)*1=10 ft2

area of part 3:

a3=length*width=8*2=16 ft2

total shaded area : a1+a2+a3=41 ft2

total area of the reactangle : a=16*8=128 ft2

total area of the nonshaded region : 128-41=87 ft2