Problem Solving

1. A thin conveyor belt 15 feet long is drawn tightly around two circular wheels each 1 foot in diameter. What is the distance, in feer between the centers of the two wheels?
2. In a survey of students, each student selected from a list of 12 songs the 2 songs that the student liked best. If each song was selected 4 times, how many students were surveyed?
3. In the xy-coordinate plane, line l and line k intersect at one point (4,3). Is the product of their slope negative?
1)The product of the x-intercept of line l and k is positive
2) The product of the y-intercept of line l and k is negative

Your help will be greatly appreciated!!

1. A total length of 15 is wound around 2 circles near each other.

Pi*r + 2*L + Pi*r = 15

Pi*1/2 + 2*L + Pi*1/2 = 15
L= (15 - pi)/2

Thanks for your reply! But I dont know why the answer for it was (15 - Pi)/2

Anurag@Gurome wrote:
The diameter = 1.
So, radius = 1/2.
Or, pi*1/2 + 2*L + pi*1/2 = 15.
Or L = (15 - pi)/2.

Thanks a lot, Anurag. Careless me! Now I know why I dont hit 50 in quant on my tests. :-/