Answer:
21 years
Step-by-step explanation:
Given
[tex]Initial\ Height = 4\frac{1}{2}[/tex]
[tex]Final\ Height = 40[/tex]
[tex]Difference = 1\frac{3}{4}[/tex]
Required
Determine the years it'll take to grow to the final height
This question depicts arithmetic progression and will be solved using
[tex]T_n = a + (n - 1)d[/tex]
Where
[tex]T_n = 40[/tex]
[tex]a = 4\frac{1}{2}[/tex]
[tex]d = 1\frac{3}{4}[/tex]
Substitute these values in the given formula;
[tex]40 = 4\frac{1}{2} + (n - 1)1\frac{3}{4}[/tex]
Convert all fractions to decimal
[tex]40 = 4.5 + (n - 1) * 1.75[/tex]
Open Brackets
[tex]40 = 4.5 + 1.75n - 1.75[/tex]
Collect Like Terms
[tex]1.75n = 40 - 4.5 + 1.75[/tex]
[tex]1.75n = 37.25[/tex]
Divide both sides by 1.75
[tex]n = \frac{37.25}{1.75}[/tex]
[tex]n = 21.2857142857[/tex]
[tex]n = 21[/tex] (Approximated)
