Multiple choice

If the average height of men in a hall is (180) cm and that of women is (150) cm if the average height of the gathering is (165) cm, then find the number of women present in the hall if the number of men present in the hall are (78)?

  1. 68

  2. 78

  3. 58

  4. 88

  5. 86
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Let w = number of women. Using weighted average formula: (180×78 + 150×w)/(78+w) = 165. Multiply both sides: 14040 + 150w = 165(78+w) = 12870 + 165w. Rearranging: 14040 - 12870 = 165w - 150w, so 1170 = 15w, giving w = 78.

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