a*****g
发帖数: 1320 | 1 1.At Marsh Mel Low Middle School 34 students play soccer, 36 students play
football and 29 students play basketball. Of these students 15 play both
soccer and football, 18 play both basketball and football and 13 play both
soccer and basketball. What is the smallest possible number of students
thatplay all three sports?
2. If x and y are two triangular numbers less than 100 that when added,
produce a sum that is a square number, what is the largest possible value of
x or y?
3. Suppose that six brothers (George, John, Thomas, Fred, Andrew, Martin)
each roll a fair 6-sided die. At least three of them have rolled an even
number. What is the probability that John, Fred and Martin have each rolled
an even number? Express your answer as a common fraction. | c*b
发帖数: 3126 | 2 1.A -> soccer, B -> football, C -> basketball
假设同时玩ABC的有x人，如何求玩A的有多少人呢？
玩A和B的 + 玩A和C的 - 被重复计算的x <= 34 （因为还可能有人只玩A不玩别的）
15 + 13 - x <= 34
同理，
15 + 18 - x <= 36
13 + 18 - x <= 29 | s*o
发帖数: 257 | 3 不明白为什么这些帖子发在多个版面。。。
of
【在 a*****g 的大作中提到】
: 1.At Marsh Mel Low Middle School 34 students play soccer, 36 students play
: football and 29 students play basketball. Of these students 15 play both
: soccer and football, 18 play both basketball and football and 13 play both
: soccer and basketball. What is the smallest possible number of students
: thatplay all three sports?
: 2. If x and y are two triangular numbers less than 100 that when added,
: produce a sum that is a square number, what is the largest possible value of
: x or y?
: 3. Suppose that six brothers (George, John, Thomas, Fred, Andrew, Martin)
: each roll a fair 6-sided die. At least three of them have rolled an even
| r*******e
发帖数: 7583 | 4 lz是一位辅导孩子数学的文科妈妈，不容易的
play
both
value
【在 s*o 的大作中提到】
: 不明白为什么这些帖子发在多个版面。。。
:
: of
| s*o
发帖数: 257 | 5 那就发一个版面比较好，一文多发，还不是转载，总感觉有点那啥。。。
【在 r*******e 的大作中提到】
: lz是一位辅导孩子数学的文科妈妈，不容易的
:
: play
: both
: value
| a******e
发帖数: 36306 | 6 买买提规定不能转载超过三个版面
【在 s*o 的大作中提到】
: 那就发一个版面比较好，一文多发，还不是转载，总感觉有点那啥。。。
| l******n
发帖数: 55 | 7 这种妈妈一般都是自己把自己感动了，至于效果吗就无所谓了。
【在 r*******e 的大作中提到】
: lz是一位辅导孩子数学的文科妈妈，不容易的
:
: play
: both
: value
| a*****g
发帖数: 1320 | 8 Not everybody would like to answer my questions.You know the probability.
Sometimes, their answers are different and I need to dertimine which one is
right. Normally, I post them in SF, Seattle and THU because the smartest
people over there and THU is my priority board.
【在 s*o 的大作中提到】
: 不明白为什么这些帖子发在多个版面。。。
:
: of
| a*****g
发帖数: 1320 | 9 Thank you ! Thank you!
【在 c*b 的大作中提到】
: 1.A -> soccer, B -> football, C -> basketball
: 假设同时玩ABC的有x人，如何求玩A的有多少人呢？
: 玩A和B的 + 玩A和C的 - 被重复计算的x <= 34 （因为还可能有人只玩A不玩别的）
: 15 + 13 - x <= 34
: 同理，
: 15 + 18 - x <= 36
: 13 + 18 - x <= 29
|
|
