Answer:
0.1274
Step-by-step explanation:
Let X be the random variable that measures the number of children who get their own coat.
Then, the expected value of X is
E[X] = 1P(X=1) + 2P(X=2)+3P(X=3)+...+10P(X=10)
The probability that a child gets her or his coat is
P(X=1) = 1/10
To compute the probability that 2 children get their own coat, we notice that there are 10! possible permutations of coats. The two children can get their coat in only one way, the other 8 coats can be arranged in 8! different positions, so the probability that 2 children get their own coat is
P(X=2) = 8!/10! = 1/(10*9) and
2P(X=2) = 2/(10*9)
Similarly, we can see that the probability that 3 children get their own coat is
P(X=3) = 7!/10! = 1/(10*9*8) and
3P(X=3) = 3/(10*9*8*7)
and the expected value of X would be
E[X] = 1/10 + 2/(10*9) + 3/(10*9*8)+...+10/10! = 0.1274
3/5 of 300 is 180. 180 coupons were unused.
A, because anything with a dilation will not be congruent as the original PQR :))
Hello,
The answer is "16".
Reason:
Just divide 12 by 3/4:
12×4=48÷3=16
1×3=3÷3=1
16/1=16
Therefore they can make 16 pizza crusts!
If you need anymore help feel free to ask me!
Hope this helps!
~Nonportrit
