Answer:
16/25 = 0.64 = 64%
Step-by-step explanation:
If we want the probability of Fiona waking up before 8am for at least one of the days, we can calculate the probability of she not waking up 8am in both days, and then we do 1 minus this probability.
The probability of she not waking up 8am in one day is (1 - 2/5) = 3/5
The probability of she not waking up 8am in both days is 3/5 * 3/5 = 9/25
So, the probability of Fiona waking up before 8am for at least one of the days is (1 - 9/25) = 16/25 = 0.64 = 64%
To solve for the variable "w" you only need to use algebra to get it alone on one side of the equals sign.
Answer:

Step-by-step explanation:
For the surface area we need to add up all the areas in the pyramid:
- area of the triangle sides (there are 4 triangles)
Area of the base:
the base is a square, and the area of a square is given by:

where
is the length of the side:
, thus:

Area of the triangles:
one triangle has the area given by the formula:

where
is the base of the triangle: 
and
is the height of the triangle:
, thus we have the following:

the expression that represents the surface area of the pyramid is:

substituting our values:

which is option B
Step-by-step explanation:
6+ 7•log2 x = 21
7.log2 x = 21-6
7. log2 x = 15
log2 x = 15/7
x = 2^(15/7)
x = 4.416 = 4.42
Now, this is for 3 months, and we're assuming, I guess it doesn't really matter, but using simple interest.
now, 3 months is not even a year, there are 12 months in 1 year, so 3 months is 3/12 years, or 1/4.