Answer: it will take 9 days
Step-by-step explanation:
The water level was initially at 34feet it was receding at the rate of a foot per day. The rate at which it was receding is linear, thus, it is in an arithmetic progression. The formula for the nth term of an arithmetic progression is expressed as
Tn = a+(n-1)d
Where
a is the first term if the sequence
d is the common difference
n is the number of terms.
From the information given,
a = 34 feet because it is the initial height
n is the number of days it will take to get to 26 ft
d = -1 because it is decreasing by 1 foot per day.
Tn = T26 = 26 feet. Therefore, the equation will be
Tn = 34 -1(n-1)
To find for T26,
26= 34 + (n - 1)-1
26 - 34 = -n + 1
n - 1 = 8
n = 8 + 1 = 9
