Answer: 3 11/12
Explanation: convert the fractions 1/4 and 1/3 to fractions with a denominator of 12. Your fractions become 3/12 and 4/12. Subtract 4/12 from 5 3/12 and get 4 11/12. Subtract one and get 3 11/12.
D- 1.65 per hot dog
Take the amount of the bag of chips which is 1.25 and multiply it by 5 because that’s how many people there are and they each bought one bag
1.25 x 5= 6.25
Next you want to subtract that amount from the total so we can just have the amount of money spent on hot dogs
22.27-6.25=16.50
Then you want to divide 16.50 by 5 because they all bought the same amount of hot dogs and this will get us to the amount of to hot dogs
16.50/5=3.30
Finally you want to divide 3.30 by 2 which will get us the price for 1 hot dog
3.30/2=1.65
There you go!!
Answer:
Step-by-step explanation:
x = y - 2.........(1)
4x + y = 2......(2)
Substituting x in (1) in (2)
4(y - 2) + y = 2
4y - 8 + y = 2
5y = 2 + 8
5y = 10
y = 10/5
y = 2
Putting x in (1)
x = y - 2
x = 2 - 2
x = 0
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
