Answer: 
Step-by-step explanation:
Here, According to the question, The population of the world is 4 billion (approx).
Again According to the question, The world's population has grown at an average rate of 1.9 percent per year since 1945.
Therefore, after 1975 the growth rate will remains same.
Thus, the population of the world after t years,
(By the formula 
)
⇒
Where 1.019 is the growth rate and 4 billion is the initial population.
Answer: 
Step-by-step explanation:
Given: A tourist first walked 17km with a speed of v km/h.
Since 
therefore, 
Let 
be the time he walked with speed v.
then 
Also he hiked 12 km uphill with the speed that was 2 km/hour less than his original speed.
Let 
be the time he hiked 12 km,
Then 
The total time for the whole trip is given by:-
Substitute the values of and in the equation, we get
Answer:10
Step-by-step explanation:
6+4=10
Answer:
Answer is third option no.4
Answer:
9
Step-by-step explanation:Replace the variable
x with −
3 in the expression. f
(
−
3
) = (
−
3
)
2 Simplify (−
3
)
2
. Remove parentheses. (
−
3
)
2 Raise −
3 to the power of 2
.
9
