My son's math - help?

Neither of us could figure these out. I'd like to be able to help him with them and check the answers - could you help with that? It would be very much appreciated.





For 1 and 2, there's a set of cards with the letters G E O M E T R Y on them.





1. You randomly select two cards from those at the right, replacing the first before you select the second. Find the probability you select two E’s.





A. 1/64


B. 1/28


C. 1/16


D. 1/56





2. You randomly select two cards from those at the right, not replacing the first before you select the second. Find the probability you select two E’s





A. 1/64


B. 1/28


C. 1/16


D. 1/56





3. How many ways can Leonardo select 3 movies to rent from the top 10 rentals?





A. 720 ways


B. 240 ways


C. 90 ways


D. 120 ways





4. How many ways can Leonardo select 3 movies to rent from the top 10 rentals and arrange them into a triple feature?





A. 720 ways


B. 240 ways


C. 90 ways


D. 120 ways





COLOR ---- NUMBER OF SHIRTS


Blue _________ 8


Red _________ 7


White _________ 12


Other _________ 3





5. The table shows the shirt colors of a random sample of


students in your school. Find the experimental probability


a student chosen at random is wearing a white shirt.





A. 4/14


B. 2/5


C. 1/10


D. 7/30





6. You want to find out who is likely to win the election for


student council president in your school.Which survey plan


describes the best sample?





F. You survey students in your social studies class.


G. You survey students in Drama Club.


H. You survey students outside the cafeteria during lunch hour.


J. You survey basketball players.





7. From 80,000 jars produced, a manufacturer samples 1,200 and finds 7 of


those defective. Estimate the total number of defective jars.

My son's math - help?
I'm gonna say 1 is B





5 is B as well





6 is H the "lunch hour" one





and the others i've got no idea. i'd have to see the sheet first. some of the info is missing. if that's how they gave it to your on then that school is whack





get him outta there
Reply:1) In "or" statements, add. In "and" statements, multiply.


This problem is an and statement because you want an E and an E. 2/8 times 2/8 = 4/64 = 1/16





2) This problem is different from the first because we don't put the E back into the mix before we choose again. That means that we will now multiply 2/8 times 1/7 (there is only one e and 7 letters left). 2/56 = 1/28





3) We are selecting three movies. Order doesn't matter. We have ten choices for the first pick, nine choices for the second pick, and eight choices for the third pick. 10x9x8 = 720.





4) This time order does matter because it asks how they can be arranged. So we take 720 and divide it by 3x2x1. 720 divided by 6 is 120.





5) 12 out of 30 people are probably wearing a white shirt. This reduces to 2/5





6) F G and J only target a small portion of the population. You are likely to get a better sample outside the cafeteria because, presumably, all the students will be at lunch.





7) if 7 out of 1200 are defective, x out of 80,000 are defective. Write this as two fractions and cross multiply to find out how many of the 80,000 are probably defective.
Reply:1) 1/4 * 1/4 = 1/16


2) 1/4 * 1/7 = 1/28


3) 10 * 9 * 8 = 720


4) 720/6 = 120


5) 12/30 = 2/5


6) Sample outside the cafeteria. It's the most random.


7) 7/1200 * 80000 = 467
Reply:1 = C ( 2/8 * 2/8)


2 = B (2/8 * 1/7)


3 = A


4 = D (3 %26amp; 4 ARE HARD TO EXPLAIN.....)


5 = B (12/30 [ 30 comes from adding the four colors together])


6 = H (most random people -- not a clique)


7 = 467 jars (set up a porportion of 7 over 1200 = x over 80000, cross multiply and get 7 * 80000 = 1200x, simplify to 560000 = 1200x, divide both sides of the equasion by 1200 and get 466.66666 and round up to 467 [because you can't have 2/3 of a jar)











i really hope this helps
Reply:first see how many Es there are for #1. there are 2. and there are 8 letters so for the first card that is 1 out of 8 then you selent the second card and that is 1 out of 8 because you replace the card u took so that is 1 out of 8 and then u multiply them them and that is 1 out of 64. and i think that is how it works but i am not 100% sure.





for #2 u do the same except u do not replace the second card so that would be 1 out of 8 multiplied by 1 out of 7 and that is 1 out of 56.





for #3 there are 10 movies and u need to select 3 so for the first movie there are 10 possible choices and for the second there are 9 possible choices because u already chose 1 and for the third there are eight possible choices because u took 2 out and so basically that is 10x9x8=720





i dont know #4





#5 u just add them all up and then make it into a fraction and then simplify.





#6 is H because it offers a wider variety.





#7 it is just 7 out of 1200 = X out of 80,000.