Question

Suppose 40 percent of Senegal's population speaks Wolof as a first language. If that's about 5 million people, approximately what is Senegal's population? Express your answer in scientific notation

Answer 1

Let the total population of Senegal be represented by the letter "x".

Now, we are given that 40% of x=5 million.

This can be rewritten as: $\frac{40}{100}x=5000000$

$0.4x=5000000$

$x=\frac{5000000}{0.4} =12500000$

This can be represented in the scientific notation as:

$x=1.25\times 10^{7}$

Thus Senegal's population in scientific notation is $1.25\times 10^{7}$

Answer 2

5 million = 5*10^6

40% * x = 5*10^6

x = (5*10^6)/0.4  = (5/0.4)*10^6  = 12.5 * 10^6  = 1.25 *10^7