How many men paid for a total amount of $262,143.75 if the first person to arrive only paid 25 cents?

Problem
In a fund raising show, a group of philanthropists agreed that the first one to arrive would pay 25¢ to enter, and each later would pay twice as much as the preceding person. The total amount collected from all of them was \$262,143.75. How many of them paid?

Find the probability that somebody is healthy given that they have positive test result?

Problem
A disease is known to affect 1 in 10,000 people. A screening test for the disease shows a positive result for 99% of the people with the disease. The test also shows positive for 2% of people who do not have the disease. Find the probability that somebody is healthy given that they have positive test result?

A.   99.51% C.   46.32%
B.   12.32% D.   78.36%

 

Find the equation of the curve passing through the point (3, 2) and having s slope 5x^2 - x + 1 at every point (x, y)

Problem
Find the equation of the curve passing through the point (3, 2) and having s slope 5x2 - x + 1 at every point (x, y).

A.   $y = \frac{5}{3}x^3 - \frac{1}{2}x^2 + x - \frac{31}{3}$ C.   $y = 5x^3 - 2x^2 + x - 118$
B.   $y = 5x^3 - 2x^2 + x - 31$ D.   $y = \frac{5}{3}x^3 - \frac{1}{2}x^2 + x - \frac{83}{2}$

 

A coin is so unbalanced that you are likely to get two heads in two successive throws as you are to get tails in one

Problem
A coin is so unbalanced that you are likely to get two heads in two successive throws as you are to get tails in one. What is the probability of getting heads in a single throw?

A.   0.168 C.   0.681
B.   0.618 D.   0.816