Answer: The sum that will be the upper limit of this population is 1280.
Step-by-step explanation:
Since we have given that
Initial population a₁ = 960
Common ratio =
So, We have to write the sum in sigma notation:
Since
so, the sum is convergent, then,
Hence, the sum that will be the upper limit of this population is 1280.
First, find the amount of time is taken to travel 1 mile :
time taken to travel 1 mile = 20/6 = 3 ⅓ mins
hence, time taken to travel 9 miles = 3 ⅓ x 9 = 30 mins
time taken to travel 10 miles = 3 ⅓ x 10 = 33 ⅓ mins