Randy has 4 pennies, 2 nickles, and 3 dimes in his pocket. if he randomly chooses 2 coins, what is the probability that they are both dimes if he doesn’t replace the first one?

1/12

Step-by-step explanation:

This is a case of joint probability.

There are a total of (4 + 2 + 3) coins in his pocket:  9 coins.

The prob. of his choosing a dime on the first selection is 3/9, or 1/3, since there are 3 dimes out of a total of 9 coins.

Now there are 8 coins, 2 of which are dimes.  The prob. of choosing a dime on the 2nd selection is 2/8, or 1/4.

The joint probability is thus (1/3)(1/4) = 1/12.

walter needs to make at least 5 more cookies but no more than 40. 5 ≤ x ≤ 40

step-by-step explanation:

20 ≤ x + 15 ≤ 55

subtract 15 from all parts

20-15 ≤ x + 15-15 ≤ 55-15

5 ≤ x ≤ 40

this means how many more cookies he has to make

walter needs to make at least 5 more cookies, but no more than 40 cookies; 5 ≤ x ≤ 40