Exam rooms A and B are located on the same floor. The number of pupils in each room is the same if 10 students are sent from A to B. If 20 candidates are transferred from B to A, the number of students in A is double that of B. Room A has the following number of students:
A. 20
B. 80
C. 100
D. 200
Answer:C
Exam rooms A and B are located on the same floor. The number of pupils in each room is the same if 10 students are sent from A to B. If 20 candidates are transferred from B to A, the number of students in A is double that of B. Room A has the following number of students:
A. 20 B. 80 C. 100 D. 200
Explanation: Let x and y represent the number of students in rooms A and B, respectively.Then x - 10 Equals y + 10 x - y = 20 x - y = 20 x - y = 20 x - y = 20 x - y = 20 (i),x + 20 = 2(y - 20) x - 2y = -60, and x + 20 = 2(y - 20) x - 2y = -60.... (ii),We get x = 100 and y = 80 when we solve I and (ii).A = 100 is the required response.