Answer:
The train can be made up in a total of
ways
Step-by-step explanation:
FIrst, lets assume that all cars are distinct. If that is the case, then, since we have a total of 8 cars, we have
- 8 possibilities for the first car
- 7 possibilities for the second car
- 6 possibilities for the third car
and so on.
So we have a total of 8! = 8*7*6*...*3*2*1 possibilities to make a train.
Now lets take into account that 5 of the cars are identical within each other. Then we could make a permutation of those 5 cars and we wouldnt notice. Hence, the order of the 5 cars of second-class doesnt matter and as a result, we should divide 8! by the total of possible permutations of the 5 second class cars, that it, 5!
We also need to divide the result by 2! = 2, because which first class car came first doesnt matter either. Therefore, the train can be made up in a total of
ways.
<u>n=6</u>
Answer:
Solution given:
The coefficient of x^2=60
we have,

we get x² in 3rd term,so
3rd term of (1+2x)^n is C(n,2)*1^n-2)(2x)^2=C(n,2)4x²
since 1^n is 1.
we have a coefficient of x^2 is 60, so
C(n,2)4=60
C(n,2)=60/4
=15
=15
n(n-1)=15*2
n^2-n=30
n^2-n-30=0
doing middle term factorization
n^2-6x+5x-30=0
n(n-6)+5(n-6)=0
(n-6)(n+5)=0
either n-6=0
n=6
or,
n+5=0
n=-5 since n>0
so neglected.
<u>So the value of n is 6.</u>
Step-by-step explanation:
Answer:
i think . it is c
Step-by-step explanation:
Answer is C as all other choices are even numbers therefore make the equation non-integer.
Answer:
-1/4x
Step-by-step explanation:
11-12/6-2 = -1/4