10 cards are numbered from 1 to 10 and placed in a box. one card is selected at random and is not replaced. another card is then randomly selected. what is the probability of selecting two prime numbers?

a. 2/15

b. 4/18

c. 7/90

d. 1/10

2/15.

Step-by-step explanation:

The  prime numbers in the first 10 numbers are: 2, 3, 5, 7 . That is a total of 4.

Prob( first number drawn is prime) = 4/10 = 2/5.

Prob( second number drawn is prime) = 3/9 = 1/3.

Required probability  is 2/5 * 1/3

= 2/15.

option (b) is correct

step-by-step explanation:

to find the solution of this system, we need to convert it into reduced row-echelon form. we have,

after applying row operations r2 -> r2/2 and r3 -> r3/3, we get,

change of stock price/initial stock price on friday * total stock value = change of stock value

0.89/73.73 *x = 42.72

x=3539.04 = total stock value at initial stock price on friday .

total stock value at initial stock price on friday/ initial stock price on friday = number of shares

3539.04/73.73 = 48 shares

they own 48 shares of this stock