Check out some similar questions!

starfirefly · Jan 4, 2008, 08:27 PM

On calgary's first New Year's Eve, some of calgary's citizens planted a pine tree in the old Woods to commemorate the first New Year's celebration. The tree was just a sapling; the trunk was cone-shaped, and its circumference at the base was 14 cm and its height was 124 cm.

Every year since then, its height has increased 45% over the previous year, and its circumference has increased 22%. If the density of the wood is 530 kilogrammes per cubic metre, how many kilogrammes did the tree's trunk weigh this past New Year's Eve?

jiten55 · Jan 4, 2008, 10:40 PM

WHEN WAS calgary's first New Year's Eve? You should tell us that.

Volume of a cone is 1/3 pi r^2 h

After n years, r becomes r * (1.22)^n and h becomes h*(1.45^n) (* means multiplication)

Volume becomes: 1/3 * pi * r^2 * (1.22)^2n * h*(1.45^n) cubic metre

Weight becomes = 530 times Volume

Substitute values of n, r (in metres), h (metres) and of course pi

(Note that 2pi r = .14 metre and h = 1.24 metre)

starfirefly · Jan 4, 2008, 10:44 PM

? I still don't get it

starfirefly · Jan 4, 2008, 10:45 PM

And I think its 9 years sorry about that I missed that part

jiten55 · Jan 5, 2008, 03:47 AM

You should try to understand a simple fact:

If something increases by x % every year, and starting value of the same is V, then in n years
V will become V (1+x/100)^n

You will not be able to do calculation in this particular case until you know
what is the value of n! So you must find out the number of years involved.