a*****g
发帖数: 1320 | 1 )If MINH picks a letter of the alphabet at random, what is the probability it occurs in the name "HETTIESBURG, MISSISSIPI"? Express your answer a common fraction.
2) Three fair six-sided number cubes, each with faces labeled 0,2,4,6,8,10, are rolled. What is the probability that the sum of the numbers rolled is greater than 20? Express your answer as a common fraction.
3) In the patterns of dots with p1,p2,p3 and p4, each successive pattern of dots has one more row and one more column. What is the ratio of the number of dots in p50 to the number of dots in p25? Express your answer as a common fraction. | a*****g
发帖数: 1320 | 2 ONE MORE: HOW MANY FIVE DIGIT INTERGERS ARE PERFECT SQUARE?
PROBABILITY
【在 a*****g 的大作中提到】
: )If MINH picks a letter of the alphabet at random, what is the probability it occurs in the name "HETTIESBURG, MISSISSIPI"? Express your answer a common fraction.
: 2) Three fair six-sided number cubes, each with faces labeled 0,2,4,6,8,10, are rolled. What is the probability that the sum of the numbers rolled is greater than 20? Express your answer as a common fraction.
: 3) In the patterns of dots with p1,p2,p3 and p4, each successive pattern of dots has one more row and one more column. What is the ratio of the number of dots in p50 to the number of dots in p25? Express your answer as a common fraction.
| l***o
发帖数: 7937 | 3 也许有人会帮你，但请不要全部用大写。
PROBABILITY
【在 a*****g 的大作中提到】
: ONE MORE: HOW MANY FIVE DIGIT INTERGERS ARE PERFECT SQUARE?
:
: PROBABILITY
| a*****g
发帖数: 1320 | 4 Done. Many thanks.
【在 l***o 的大作中提到】
: 也许有人会帮你，但请不要全部用大写。
:
: PROBABILITY
| m******y
发帖数: 800 | 5 １，２用排列组合，不难，
第３题，没看明白，是p１一个点，p２四个点，p３九个点，以此类推么？ | G*******m
发帖数: 16326 | 6 P1=1
Pn=n*n
Pn+1=n*n+(n)+(n+1)=(n+1)(n+1)
P25=25*25
P50=50*50
ratio=1/4 | G*******m
发帖数: 16326 | 7 All cases = 3P6 = 6 * 6 * 6 = 216 (permutation, order dependent)
qualified cases = 35
probability = 35/216
first cube: qualified cases
0 0
2 1 (2 10 10)
4 3 (1+2) (4 10 8, 4 10 10)
6 6 (1+2+3) (6 10 6, 6 10 8, 6 10 10)
8 10 (1+2+3+4) (8 10 4, 8 10 6, 8 10 8, 8 10 10)
10 15 (1+2+3+4+5) | G*******m
发帖数: 16326 | 8 10000=100*100
99856=316*316
100489=317*317
so total 5 digit integers = 316 - 100 + 1 = 217 | a*****g
发帖数: 1320 | 9 你就是我要找的人！ 谢谢股票大牛！！！
【在 G*******m 的大作中提到】
: 10000=100*100
: 99856=316*316
: 100489=317*317
: so total 5 digit integers = 316 - 100 + 1 = 217
| a*****g
发帖数: 1320 | 10 第３题 我现在懂了，我应该画个图的，没错，就是以此类推，谢谢你。
【在 m******y 的大作中提到】
: １，２用排列组合，不难，
: 第３题，没看明白，是p１一个点，p２四个点，p３九个点，以此类推么？
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