Một Người Có 10 Đôi Giày Khác Nhau

     
Một người có 10 đôi giầy khác nhau vàtrong lúc đi phượt vội vã lấy bỗng nhiên 4 chiếc.Tính phần trăm để vào 4 chiếc giầy lấy ra có tối thiểu một đôi.
*

GọiA" role="presentation" style="display: inline-block; line-height: 0; font-size: 18.06px; word-wrap: normal; word-spacing: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; padding-top: 1px; padding-bottom: 1px; position: relative;">AAlà phát triển thành cố4" role="presentation" style="display: inline-block; line-height: 0; font-size: 18.06px; word-wrap: normal; word-spacing: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; padding-top: 1px; padding-bottom: 1px; position: relative;">44chiếc lấy ra thuộc4" role="presentation" style="display: inline-block; line-height: 0; font-size: 18.06px; word-wrap: normal; word-spacing: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; padding-top: 1px; padding-bottom: 1px; position: relative;">44đôi khác nhau

Ta tínhn(A)" role="presentation" style="display: inline-block; line-height: 0; font-size: 18.06px; word-wrap: normal; word-spacing: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; padding-top: 1px; padding-bottom: 1px; position: relative;">n(A)n(A):

+ Chọn4" role="presentation" style="display: inline-block; line-height: 0; font-size: 18.06px; word-wrap: normal; word-spacing: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; padding-top: 1px; padding-bottom: 1px; position: relative;">44đôi trong10" role="presentation" style="display: inline-block; line-height: 0; font-size: 18.06px; word-wrap: normal; word-spacing: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; padding-top: 1px; padding-bottom: 1px; position: relative;">1010đôi :C104=210" role="presentation" style="display: inline-block; line-height: 0; font-size: 18.06px; word-wrap: normal; word-spacing: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; padding-top: 1px; padding-bottom: 1px; position: relative;">C410=210C104=210cách.

+ Mỗi song (trong4" role="presentation" style="display: inline-block; line-height: 0; font-size: 18.06px; word-wrap: normal; word-spacing: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; padding-top: 1px; padding-bottom: 1px; position: relative;">44đôi trên) chỉ chọn1" role="presentation" style="display: inline-block; line-height: 0; font-size: 18.06px; word-wrap: normal; word-spacing: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; padding-top: 1px; padding-bottom: 1px; position: relative;">11chiếc :24=16" role="presentation" style="display: inline-block; line-height: 0; font-size: 18.06px; word-wrap: normal; word-spacing: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; padding-top: 1px; padding-bottom: 1px; position: relative;">24=1624=16cách.

⇒n(A)=210.16=3360" role="presentation" style="display: inline-block; line-height: 0; font-size: 18.06px; word-wrap: normal; word-spacing: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; padding-top: 1px; padding-bottom: 1px; position: relative;">⇒n(A)=210.16=3360⇒n(A)=210.16=3360

⇒P(A)=3360C204=224323" role="presentation" style="display: inline-block; line-height: 0; font-size: 18.06px; word-wrap: normal; word-spacing: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; padding-top: 1px; padding-bottom: 1px; position: relative;">⇒P(A)=3360C420=224323⇒P(A)=3360C204=224323

Xác suất bắt buộc tính là1−P(A)=99323" role="presentation" style="display: inline-block; line-height: 0; font-size: 18.06px; word-wrap: normal; word-spacing: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; padding-top: 1px; padding-bottom: 1px; position: relative;">1−P(A)=99323