David boards an elevator on the 11th level of a skyscraper and speeds up to 57 floors per minute. Albert, on the other hand, boards an elevator on the 51st level of the same building and descends at a speed of 63 floors per minute. Which floor will their paths intersect if they continue to move at this rate?
A. 19
B. 28
C. 30
D. 37
Answer:C
David boards an elevator on the 11th level of a skyscraper and speeds up to 57 floors per minute. Albert, on the other hand, boards an elevator on the 51st level of the same building and descends at a speed of 63 floors per minute. Which floor will their paths intersect if they continue to move at this rate?
A. 19 B. 28 C. 30 D. 37
Explanation: Let's say their paths intersect in x minutes.After that, 11 + 57x = 51 - 63x 120x = 40,1/3 = x,Number of floors David covered in (1/3) minutes = 1/3 x 57 = 19.As a result, their trajectories meet at (11 + 19), which is the 30th floor.