Recently, the fish population has been going down because of an oil spill in the ocean. To monitor the current population in a certain region, Danielle collects 84 fish, tags them, and releases them. Later, she collects 480 fish and finds that 16 of them are tagged.

, 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

the answer is a.

step-by-step explanation:

in three games of golf, alex shot two under par four times.

answer: the resulting cross section is a rectangle. solution: a plane parallel to the base of a triangular prism will intersect a cross section that is the same shape as its bases. so the cross section is a triangle.

step-by-step explanation:

answer: answer is b.

[m < b = 120º]

step-by-step explanation: