Question

1.69 Номер помогите пожалуйста.Даю 40б

Answer 1

(C₁₆³+C₁₅²+C₁₄¹)/(C₁₆⁴+C₁₅³+C₁₄²)
C₁₆³=16!/((16-3)!*3!)=13!*14*15*16/(13!*6)=3360/6=560
C₁₅²=15!/((15-2)!*2!)=15!/(13!*2)=13!*14*15/(13!*2)=210/2=105
C₁₄¹=14!/((14-1)!*1)=14!/(13!*1)=13!*14/13!=14
(C₁₆³+C₁₅²+C₁₄¹)=560+105+14=679.
C₁₆⁴=16!/((16-4)!*4!)=12!*13*14*15*16/(12!*24)=43680/24=1820
C₁₅³=15!/((15-3)!*3!)=12!*13*14*15/(12!*6)=2730/6=455
C₁₄²=14!/((14-2)!*2!)=12!*13*14/(12!*2)=182/2=91
C₁₆⁴+C₁₅³+C₁₄²=1820+455+91=2366
679/2366=97/338.
Ответ: 97/338.