Final answer:
The prices of Stock A and Stock B will be equal 8 hours after 9 A.M., which is not listed in the provided options. The question gives an incorrect set of answers, as none match the correct calculation.
Step-by-step explanation:
The question asks to calculate when the prices of two stocks will be the same given their rates of change over time. To find out when the prices of Stock A and Stock B will be equal, we can set up two linear equations based on the given information and solve for the time when both prices will be the same.
Let's define T as the number of hours after 9 A.M. for Stock A and after noon for Stock B. For Stock A, the price increases by $0.07 each hour, so its equation starting from 9 A.M. at $15.97 would be Price of Stock A = 15.97 + 0.07T. For Stock B, the price decreases by $0.09 each hour, and its price at noon is $16.72, so its equation is Price of Stock B = 16.72 - 0.09T.
Setting these two equations equal to each other gives us
15.97 + 0.07T = 16.72 - 0.09T.
By solving this equation for T, we find that T equals 5. Therefore, in 5 hours after noon, the prices of the two stocks will be the same. Since Stock A started at 9 A.M., it's already been 3 hours by noon, thus 5 + 3 equals 8 hours after 9 A.M. Answer (c) 18 hours is incorrect; the correct answer is not listed as an option as the stocks will be the same 8 hours after 9 A.M., which would be 5 P.M. on the same day.