There are 4 positions in the string that each have 25 choices (any letter in the English alphabet except A) and the other positions are filled with A, so there are 25⁴ possible strings containing exactly 7 A's.
Overall, there are 26¹¹ possible strings of length 11.
Then the probability of randomly generating a string containing exactly 7 A's is
25⁴ / 26¹¹ ≈ 0.000000000106427
Answer:
see explanation
Step-by-step explanation:
Equation for Fast Internet is
45 + 50.45x
Equation for Quick Internet is
57.95x
To find when they cost the same , equate the 2 equations
45 + 50.45x = 57.95x ← required equation
Solve the equation by subtracting 50.45x from both sides
45 = 7.5x ( divide both sides by 7.5 )
6 = x
Both services would cost the same after 6 months
Answer:
the 2nd one
Step-by-step explanation:
0<x<1 and 0<y<1
x>0 so x is positive and y>0 so y is also positive.
When you multiply two positive numbers you always get a positive number, so the product of x and y must be positive, or greater than 0.
xy>0 - it must be true
xy<0 - it can't be true
Also when you divide a positive number by a positive number you always get a positive number, so the quotient of x and y must be positive.
x/y<0 - it can't be true
D and E can be true, but don't have to. It depends on the values of x and y. If x>y, then x-y>0 is true and x-y<0 isn't true; if x<y, then x-y>0 isn't true and x-y<0 is true.
Therefore, only A <u>must</u> be true.
No solutions.
To solve, set the two equations equal to each other.
6x +9 = 6x +2
cross out the 6x
9 = 2
there are no instances where 9 = 2, so there are no solutions.