<p>I've been doing some practice tests, and I've ran into some problems that I've had some trouble on.</p>
<p>"The faces of a cube are numbered with integers from 1 to 6. If the cube is thrown twice on a flat surface, what is the probability that the sum of the tow numbers shown on the top face is greater than 7?
- The Princeton Review gives an explanation of the answer by writing out all of the combinations possible. I feel like this would take a long time, any different methods?</p>
<p>"It takes Sherry 4 hours to pick 150 apples and it takes Carol 3 hours to pick 180 apples. If they are working together, how many apples can they pick in ten hours?
- I have some trouble with rate problems. Any easy equations I can use to solve the problem?</p>
<p>"Admission to an amusement park costs $7 for a child and $15 for an adult. If 96 tickets were sold for a total of $800, what was the ratio of the number of adult's tickets sold to the number of children's tickets sold?"</p>
<p>"The average (artithemtic mean) of five positive even integers is 60. If p is the greatest of these integers, what is the greatest possible value of p?"</p>
<ol>
<li>there r 36 combinations when u throw the dice twice ( 1/6 *1/6). but there r only 18 different combinations. and 11 different sums(although this is pretty irrevlevent). 18 different combinations would mean 18 sums. so 3+4, 4+4, 3+5,4+5,5+5,5+6,6+6,3+6,4+6. and the anwser would be 1/2. i don’t know whether that’s the right anwser or not…
2.ok umm if sherry uses 4 hours to pick up 150 apples, then u need to work out the apples sherry can pick up in 1 hour, the same goes for carol. And then you add up the apples they both can pick in 1 hour and time the number to 10 because it’s 10 hours and u have ur anwser.</li>
<li>This is a pretty easy question. ok umm let’s say that the number of child tickets is X, then 7<em>X+(96-X)</em>15=800.
4.ok umm if the arithmic average is 60 then the sum of the 5 numbers would be 300. since p is the largest, u need to find the smallest that is possible for the other 4 number but u need to make these 5 all even and postive. u need to remember that umm when u add even numbers u get an even number. when u add odd numbers u get an even number, when u add an odd number to an even number, u get an odd number. so the smallest even number would be 2, then 2+2+2+2=8, then the greatest value of p would be 300-8=292.
hehe ok um i don’t know whether the anwsers r right but i did get 800s for my SATs and SAT math level 2 hehe
see if it helps oh and um if u have any other math questions just ask</li>
</ol>
<p>As to the first one, anyone who plays craps a lot could easily give you the answer to the first one. There are 36 different results (6 X 6). 7 is is the mid-value and has 6 of those potential results (1 and 6, 6 and 1, 2 and 5, 5 and 2, 4 and 3 and 3 and 4). The remaining 30 results are divided 15 possible results below 7 and 15 above 7, so probability that total will be above 7 is 15/36 or 5/9. A craps player would immediately know the chance numbers are 5 (out of 36), 4, 3, 2, 1 (which adds up to 15 out of 36) for an 8, 9, 10, 11, or 12 total respectively. </p>
<p>As to the last one, if average is 60 for five numbers they must add up to 300 (300 divided by 5 is 60). Since they are all even numbers, the lowest possible four numbers are 2, 4, 6, and 8, which add up to 20. Thus, the highest possible integer is 280. The question does not say the numbers repeat themselves and when answering you usually should not assume they do. Obviously if they can repeat then highest possible number would be 292 as noted above since you could have four 2’s.</p>