##### Combinatorics: comprobación de requisito previo

Enseñamos conceptos difíciles con las palabras más simples posibles. Vamos a corroborar que conozcas los términos y las ideas que se necesitan. Este curso es el correcto si obtienes al menos 80% en esta prueba, pero menos del 70 % de la place-out test

Tiempo restante:

10:00

1.

If $a = 2^b c$ and $b = 3$ and $c = 5,$ what is $A?$

$13$

$30$

$40$

$45$

$256$

2.

Calculate:

$\frac{6 \times 5 \times 4}{3 \times 2 \times 1}$

$\displaystyle \frac{5}{2}$

$15$

$20$

$80$

$720$

3.

All but one of these rings of 6 beads can be obtained from the others by rotating or flipping over the ring. Which is the unusual one?

4.

When buying a certain model of phone, there are $3$ colors to choose from, and $3$ different amounts of storage to choose from. How many different combinations are there for that phone model?

$6$

$9$

$27$

$64$

$720$

5.

Jenny has $3$ skirts, $2$ pants, and $4$ shirts. How many ways can she create an outfit with one of the shirts, and either a skirt or pant?

$8$

$9$

$12$

$20$

$24$

6.

Everybody in a certain middle school takes French, Spanish, or both. The French teacher has a total of $90$ students, and the Spanish teacher has a total of $110$ students. There are $20$ students in both languages. How many students are at the school?

$180$

$190$

$200$

$210$

$220$