Multiple choice

There are three persons A, B and C in a room. If a person D joins the room, the average weight of the persons in the room reduces by x kg. Instead of D, if person E joins the room, the average weight of the persons in the room increases by 2x kg. If the weight of E is 12 kg more than that of D, then the value of x is

  1. 1.5

  2. 2

  3. 0.5

  4. 1
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Let S be sum of weights of A, B, C. (S+D)/4 = S/3 - x. (S+E)/4 = S/3 + 2x. Subtracting: (E-D)/4 = 3x. Given E-D = 12, so 12/4 = 3x. 3 = 3x, x = 1.

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