Answer: 10n^2 - 10
Step-by-step explanation:
(5n - 5)(2+2n) becomes (5n-5)(2n+2)
= (5n)(2n) + (5n)(2) + (-5)(2n) + (-5)(2)
= 10n^2 - 10
Answer:
0.5j+19
Step-by-step explanation:
There are

ways of pairing up any 2 members from the pool of
contestants. Note that

so that

Answer:
P( sum is prime )= 73/216
Step-by-step explanation:
The minimum value of the sum will be 3 and maximum value will be 18. So the prime numbers in this range are 3 , 5, 7, 11, 13, 17.
P(sum=3)=1/216, P(sum=5)=6/216, P(sum=7)=15/216, P(sum=11)=27/216, P(sum=13)=21/216, P(sum=17)=3/216.
The final probability will be sum of the above given probabilities.
Hence P( sum is prime )= 73/216