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ohmygodd
Apr 10, 2013, 08:40 PM
1. How many different 5-digit zip codes are there if any of the digits 0-9 can be used WITHOUT REPETITION, but only 7 and 9 can be used on the first digit?

~can you please show the steps?Thank you!~


2. There are 7 blue pens, 3 black pens, and 2 red pens in a drawer. If you select three pens at random with NO replacement, what is the possibility that you will select a blue pen, then a black pen, then another blue pen?

~Can you please show the steps for this one too?Thank you!~

teacherjenn4
Apr 10, 2013, 08:46 PM
We can help, but we don't do the work for you. Post your attempt and we will help you from there.

ohmygodd
Apr 10, 2013, 08:56 PM
1. On this one I know I get to 79,865 with only a few repeats but that's as far as I got.

2. 7 pens/12, Then 3 pens/11, the 6 pens/10. Then I multiplied the denominators and added the numerators for 16/1,320. Is this correct?

~thank you for your help!~