Answer:
C) 3/5
Step-by-step explanation:
Have you heard of this way to memorize the trig ratios?
SOH-CAH-TOA (Say it out loud so you remember it.)
It represents these ratios:
Sine = opposite side / hypotenuse
Cosine = adjacent side / hypotenuse
Tangent = opposite side / adjacent side
In this problem, cos C = adj / hyp = BC / AC = 24 / 40.
That simplifies to 3/5
The formula for the future value of the account is
A = P(1 + r/n)^(nt)
where you have
A = 19909.20
P = 8975
r = 0.038
t = 21
The resulting equation is not one that can be solved by algebraic means, but we can use a graphing calculator to find n. This graph shows us n = 12, so
the interest compounds monthly.
An integer may be a multiple of 3.
An integer may be 1 greater than a multiple of 3.
An integer may be 2 greater than a multiple of 3.
It is redundant to say an integer is 3 greater than a multiple of 3 (that's just a multiple of 3, we've got it covered). Same for 4, 5, 6, 7...
Let's consider a number which is a multiple of 3. Clearly, we can write 3+3+3+3+... until we reach the number. It can be written as only 3's.
Let's consider a number which is 2 greater than a multiple of 3. If we subtract 5 from that number, it'll be a multiple of 3. That means we can write the number as 5+3+3+3+3+... Of course, the number must be at least 8.
Let's consider a number which is 1 greater than a multiple of 3. If we subtract 5 from that number, it'll be 2 greater than a multiple of 3. If we subtract another 5, it'll be a multiple of 3. That means we can write the number as 5+5+3+3+3+3+... Of course, the number must be at least 13.
That's it. We considered all the numbers. We forgot 9, 10, 11, and 12, but these are easy peasy.
Beautiful question.
