Answer:
The unknown number is -5.
Step-by-step explanation:
-3 + -5 = -8
-8 - -3 = -5
-8 - -5 = -3
Composite figure is made up of 4 triangles and a square.
Area of Square = Length x Length
Area of Square = 12 x 12
Area of Square= 144 cm²
Area of triangle = 1/2 x base x height
Area of triangle = 1/2 x 12 x 8
Area of triangle = 48 cm²
Area of 4 Triangles = 48 x 4
Area of 4 Triangles = 192 cm²
Total Area = 144 + 192 = 336 cm²
It would be 30 students from his class roster because not every kid would have his math class in the other options.
The question is incomplete, here is the complete question:
Recall that m(t) = m.(1/2)^t/h for radioactive decay, where h is the half-life. Suppose that a 500 g sample of phosphorus-32 decays to 356 g over 7 days. Calculate the half life of the sample.
<u>Answer:</u> The half life of the sample of phosphorus-32 is 
<u>Step-by-step explanation:</u>
The equation used to calculate the half life of the sample is given as:

where,
m(t) = amount of sample after time 't' = 356 g
= initial amount of the sample = 500 g
t = time period = 7 days
h = half life of the sample = ?
Putting values in above equation, we get:

Hence, the half life of the sample of phosphorus-32 is 
Answer: a. 0.40 b. 0.23 c . 0.435 d . 0.25
Step-by-step explanation:
melanin content Total
high low
moisture high 13 10 23
content low 47 30 77
Total 60 40 <u> </u><u>100</u>
Let A denote the event that a sample has low melanin content, and let B denote the event that a sample has high moisture content.
a) Total skin samples has low melanin content = 10+30=40
P(A)=
b) Total skin samples has high moisture content = 13+10=23
P(B) =
c) A ∩ B = Total skin samples has both low melanin content and high moisture content =10
P(A ∩ B) =
Using conditional probability formula , 

d) 
