Answer:
Step-by-step explanation:
x ≈ 4.66667
Assuming There is ONLY ONE CORRECT ANSWER,
The probability of her guessing the answer without ruling out the choices is 1/5.
if 3 choices are ruled out, then 1 out of the remaining two is right, which gives the probability 1/2
now, 1/5 = 20% , while 1/2 = 50%.
Therefore her probability of getting the correct answer improves by 30% [ not much in a REAL test though :P ]
An=a1+d (n-1)
a1= 7
find d
Let's use a2
a2=1
1=7+d (2-1)
1=7+d
-7 both sides
d=-6
explicit formula is
an=7+-6 (n-1)
a14=?
a14=7-6 (14-1)
a14=7-6×13
a14=7-78
a14=-71
Use f and m for "female" and "male." Then f = m + 16, and f + m = d (total)
So now we have the system of linear equations
f = m + 16
f + m = d
We can eliminate f by subst. m + 16 for f in the second equation:
d-16
m + 16 + m = d, or 2m + 16 = d. Find m. 2m = d - 16, so that m = --------
2
Assuming that the male horses are either brown or black, and that 25% of these are brown, then the rest must be black. This number is
d-16
0.75 [ --------- ] .
2
