1.
In 15 – 18, the sequences are arithmetic or geometric.
Find a recursive formula for the nth term.
-5, -1, 3, 7, . . .
2.
1/8,-1/4,1/2,-1,…
3.
Find an explicit formula for the nth term.
-5, -1, 3, 7, . . .
4.
1/8,-1/4,1/2,-1,…
5.
6.
Count the number of ways that each procedure can be done.
Line up 4 people (Mr. Han, Ms. Aguirre, Ms. Torres, and Mr. Birko) for a photograph.
7.
Arrange five books (English, Pre Calculus, Physics, U.S. History, and Korean) on a bookshelf.
8.
How many different answer keys are possible for a 10-question True-False Test?
9.
How many different license plates consist of five symbols, either digits or letters?
10.
Mr. Han gives 20 study questions, from which he will select 8 to be answered on the final exam. How many ways can he select the questions?
11.
The card game “bid Euchre” uses a pack of 24 cards, consisting of ace, king, queen, jack, 10, and 9 in each of the four suits (spades, hearts, diamonds, and clubs). In bid Euchre, a hand consists of 6 cards. Find the probability of each event.
A hand is all spades.
12.
All six cards are from the same suit.
13.
A hand includes all four aces.
14.
There are two precalculus sections at Roosevelt High School. There 12 girls and 8 boys in the 1^{st} period, while there are 10 girls and 15 boys in the 3^{rd} period. If a precalculus student chosen at random happens to be a girl, what is the probability she is from the 1^{st} period?
15.
If it rains tomorrow, the probability is 0.8 that John will practice his piano lesson. If it does not rain tomorrow, there is only a 0.4 chance that John will practice. Suppose that the chance of rain tomorrow is 40%. What is the probability that John will practice his piano lesson? (Hint: Use a tree diagram)
16.
Find the first 4 terms and the 20^{th} term of the sequences.
17.
18.
19.
Find the first 4 terms only.
20.
Solve the equation algebraically.
x = ?