• We need your support!

    We are currently struggling to cover the operational costs of Xtremepapers, as a result we might have to shut this website down. Please donate if we have helped you and help make a difference in other students' lives!
    Click here to Donate Now (View Announcement)

XtremePapers

Anum96
Anum96
Ask awayyyy!
I
Iris Dylan Lane
A gardener has the task of digging an area of 800m^2. On the first day, he digs an area of 10m^2. On each successive day he digs an area 1.2 times the area that he dug the previous day, until the day when the task is completed. Find the number of days needed to complete the task.
Anum96
Anum96
Can you state the answer?
I
Iris Dylan Lane
I don't know the answer..sorry
Anum96
Anum96
Okay, No problem. Give me 2 min type the solution :p
I
Iris Dylan Lane
Sure :)
Anum96
Anum96
a is 10
The common difference is 1.2
So we have the formula
s(of all terms)*equals* n/2(2a *plus* (n-1)d)
800 *equals* n/2 (2(10) *plus* (n-1)1.2)
I
Iris Dylan Lane
Acha..why isn't this g.p.?
Anum96
Anum96
It is g.p. Sorry about that. I misread it.
First term is 10
Common ratio is 1.1
And so you have
800 *equals* 10(1-1.1^n)/1-1.1
Top