Lessons

General Aptitude
10.1 Problems on H.C.F and L.C.M - General Questions

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Q.

There are two examinations rooms A and B. If 10 students are sent from A to B, then the number of students in each room is the same. If 20 candidates are sent from B to A, then the number of students in A is double the number of students in B. The number of students in room A is:

View Answer

Correct choice: C

Explanation:

Let the number of students in rooms A and B be x and y respectively.

Then, x - 10 = y + 10   ⇒   x - y = 20 .... (i)

     and x + 20 = 2(y - 20)   ⇒   x - 2y = -60 .... (ii)

Solving (i) and (ii) we get: x = 100 , y = 80.

∴ The required answer A = 100.

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