Cant figure it out, Need help.

[golu23]

4) A circular jogging track forms the edge of a lake that has diameter of 2 miles. Joe walked once around the track at the rate of 3 miles /hr. If the no of hrs t took joe to walk completely around the lake,which of the following is a correct statement.
a)0.5<t<.75
b)1.75<t<2.0
c)2.0<t<2.5
d)2.5<t<3.0
e)3<t<3.5

In a survey of 248 people 156 are married,70 are self employed and 25% of those who are married are self employed. IF a person is to be randomly selected from those surveyed, what is the probability that the person will be self employed but not married?
A)1/8 B)4/31 c) 117/248 d)1/4 e)31/117

[gmattest001]

4) A circular jogging track forms the edge of a lake that has diameter of 2 miles. Joe walked once around the track at the rate of 3 miles /hr. If the no of hrs t took joe to walk completely around the lake,which of the following is a correct statement.
a)0.5<t<.75
b)1.75<t<2.0
c)2.0<t<2.5
d)2.5<t<3.0
e)3<t<3.5

Total distance = 2*22/7*(2/2) = 6.28 miles
speed = 3 miles/Hours
Time= D/S = 6.28/3 = 2.09 (approx)
so this fit in C.



In a survey of 248 people 156 are married,70 are self employed and 25% of those who are married are self employed. IF a person is to be randomly selected from those surveyed, what is the probability that the person will be self employed but not married?
A)1/8 B)4/31 c) 117/248 d)1/4 e)31/117


"25% of those who are married are self employed" is wrong as self employees in 156 Right.

[Anurag@Gurome]

4) A circular jogging track forms the edge of a lake that has diameter of 2 miles. Joe walked once around the track at the rate of 3 miles /hr. If the no of hrs t took joe to walk completely around the lake,which of the following is a correct statement.
a)0.5<t<.75
b)1.75<t<2.0
c)2.0<t<2.5
d)2.5<t<3.0
e)3<t<3.5

Diameter of circular track = 2 miles
Now circumference of a circle = (pi) * diameter of the circle
So, the distance traveled by Joe = 2(pi) = 2 * 3.14 = 6.28 approx.
It is given that his speed = 3 mph
Time, t = distance traveled/speed = 6.28/3 = 2.09 approx

The correct answer is C.

[Anurag@Gurome]

In a survey of 248 people 156 are married,70 are self employed and 25% of those who are married are self employed. IF a person is to be randomly selected from those surveyed, what is the probability that the person will be self employed but not married?
A)1/8 B)4/31 c) 117/248 d)1/4 e)31/117

Total # of people = 248
Married people, which includes self employed and not employed = 156
Total self employed = 70
# of people who are self employed among the married people = 25% of 156 = 0.25 * 156 = 39
So, self employed people who are not married = 70 - 39 = 31

Therefore, required probability = 31/248 = [spoiler]1/8[/spoiler]

The correct answer is A.

[ronnie1985]

First question t~ 2.095
Second Question
By using Venn Diagram, M = 117, E = 31 EintM = 39
P = 31/248 = 1/8