Answer:
The number of days it take to reach half its height is 99 days
Explanation:
The given parameters are;
The height to which the beans stalk grew daily = Twice the initial height
The time duration for the bean stalk to reach maximum height = 100 days
Therefore, the growth of the bean stock is in the form of a geometric progression with a common ratio, r = 2
The formula for a geometric progression = a×r⁽ⁿ⁻¹⁾
Therefore, the height of the bean is given by the formula a×r⁽ⁿ⁻¹⁾
Where;
The first term = a = 1 (for analysis)
The number of terms (days) = n = 100 for 100 days
Therefore, we have;
After 100 days, the height of the bean = 1×2⁽¹⁰⁰⁻¹⁾ = 2⁹⁹ = 6.34 × 10²⁹
Half the height = 6.34 × 10²⁹/2 = 3.1291265 × 10²⁹
Which gives;
1×2⁽ⁿ⁻¹⁾ = 3.1291265 × 10²⁹
n - 1 = ㏒(3.1291265 × 10²⁹)/㏒(2) = 98
Which gives;
n - 1 = 98
n = 98 + 1 = 99 days.