Need to also show work but confused
1 answer:
You might be interested in
Answer: C 2.5%
Step-by-step explanation:
The "Rule of 72" is a easy way to calculate how much time an investment will take to double with a given fixed annual rate of interest.
Just we have to divide 72 by the annual rate of return(r), we can get a rough estimate of how many years it will take to double the initial investment .
Now, in given problem: Let 'r' be the rate of interest
Time to double the amount=29 years
Thus by rule 72 ,
Therefore, C is the right option.
Answer:
The height of the pole is 167 m
Step-by-step explanation:
The given parameters are;
Increase in the length of the shadow = 90 m
Initial angle of elevation of the Sun = 58°
Final angle of elevation of the Sun = 36°
We have a triangle formed by the change in the length of the shadow and the rays from the two angle of elevation to the top of the pole giving an angle 22° opposite to the increase in the length of the shadow
We have by sin rule;
90/(sin (22°) = (Initial ray from the top of the pole to the end of the shadow's length)/(sin(122°)
Let the initial ray from the top of the pole to the end of the shadow's length = l₁
90/(sin (22°) = l₁/(sin(122°)
l₁ = 90/(sin (22°) ×(sin(122°) = 283.3 m
Therefore;
The height of the pole = 283.3 m × sin(36°) = 166.52 m
The height of the pole= 167 m to three significant figures.
