The one in the first seat can be any one of 60.
For each of those . . .
The one in the 2nd seat can be any one of the remaining 59.
For each of those . . .
The one in the 3rd seat can be any one of the remaining 58.
For each of those . . .
.
.
.
The one in the 9th seat can be any one of the remaining 52.
For each of those . . .
The one in the 10th seat can be any one of the remaining 51.
Total number of ways to pick 10 students out of 60
and arrange them in 10 seats =
(60·59·58·57·56·55·54·53·52·51) = 273,589,847,200,000,000.
(rounded to the nearest hundred million ways)
Number of ways to pick 10 students out of 60,
no matter how they sit =
(60·59·58·57·56·55·54·53·52·51) / (10·9·8·7·6·5·4·3·2)
= 75,394,027,560. (rounded to the nearest 10 ways)
Answer:
106.67 hours
Step-by-step explanation:
Total hours
160 * 8 = 1,280
Hours for group of 12
1280 / 12 = 106.6666666667
Answer:
-8
Step-by-step explanation:
