The rabbit population in a certain area is 500% of last year's population. There are 900 rabbits this year. How many were there last year?

, and

for

step-by-step explanation:

we can analyze the pattern at which the terms increase. let us denote , , , so that we can call

note the following:

the pattern: to get the next term value, we just add the next term number (e.g. 1st, 2nd, to the previous term value (term values are the given numbers in the question, 1, 3, 6, 10, 15,

from , to get to , we add

from , to get to , we add

etc.

we need to form a recursive formula, a formula that has the next term as a function of the previous term. so a possible recursive formula can be

, and for

answer: both chords and diameters have two endpoints on a circle. diameters must intersect the center of a circle.

answer: the four apples you took away.

step-by-step explanation:

the answer is  

a.

4,624π mm2

step-by-step explanation: