Answer:
It costs $42.43
Step-by-step explanation:
Lets explain how to solve the problem
- The cost of
kilogram of candy is $7.5
- We need to find the cost of
kilogram
We can use the ratio to find the answer
======= Dollar : Kilogram
======= 7.5 : 
======= c :
By using cross multiplication
∴ c ×
= 7.5 × 
∵
= 
∴
= 
∴ c ×
= 7.5 × 
∴ c ×
= 
Divide both sides by 
∴ c =
÷ 
Change the division sign to multiplication sign and reciprocal the
fraction after the division sign
∴ c =
×
∴ c =
= 42.43 dollars
∵ c represents the cost of
kg
∴ It costs $42.43
Answer:
-13x+10
Step-by-step explanation:
(4x+5)(x-2)
Multiply each term in the first parenthesis by each term in the second (foil)
Step 1: Expand it by writing out each multiplication. I added a picture showing which order to do it. (go in order of green, red, blue, yellow.) (you can remember this as first, outside, inside, last.)
When you expand it'll look like: 4x⋅x+4x⋅-2-5x-5⋅-2
Step 2: Calculate product
4x⋅x+4x⋅-2-5x-5⋅-2 (for the 4x⋅x it would be written like
)
+4x⋅-2-5x-5⋅-2
+4x⋅-2-5x-5⋅-2 (4x⋅-2 becomes -8x) (multiply 4x times -2)
-8x-5x-5⋅-2
-8x-5x-5⋅-2 (-5⋅-2 becomes +10) (multiply -5 times -2)
-8x-5x+10
Step 3: collect like terms
-8x-5x+10 (-8x-5x becomes -13x) (-8x times -5x)
-13x+10 is the most simplified so it should be your final answer
Answer:
a) 0.2416
b) 0.4172
c) 0.0253
Step-by-step explanation:
Since the result of the test should be independent of the time , then the that the test number of times that test proves correct is independent of the days the river is correct .
denoting event a A=the test proves correct and B=the river is polluted
a) the test indicates pollution when
- the river is polluted and the test is correct
- the river is not polluted and the test fails
then
P(test indicates pollution)= P(A)*P(B)+ (1-P(A))*(1-P(B)) = 0.12*0.84+0.88*0.16 = 0.2416
b) according to Bayes
P(A∩B)= P(A/B)*P(B) → P(A/B)=P(A∩B)/P(B)
then
P(pollution exists/test indicates pollution)=P(A∩B)/P(B) = 0.84*0.12 / 0.2416 = 0.4172
c) since
P(test indicates no pollution)= P(A)*(1-P(B))+ (1-P(A))*P(B) = 0.84*0.88+ 0.16*0.12 = 0.7584
the rate of false positives is
P(river is polluted/test indicates no pollution) = 0.12*0.16 / 0.7584 = 0.0253
Answer:
not sure for the 1st one but pretty sure 2nd one is B
Step-by-step explanation:
Answer:
x=40
Step-by-step explanation:
you have to get a answer of 60
(40)+20=60
and 2(40)-20=60