Multiple choice

Heights of the students of a class are being measured. The average height of boys is 130 cm and the average height of girls is 120 cm. If the average height of the whole class is 127 cm, what could be the possible strength of boys and girls in the class, respectively?

  1. 7 and 3

  2. 8 and 3

  3. 7 and 4

  4. 9 and 6

  5. 9 and 5
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Using the allegation method: (130-127) / (127-120) = 3 / 7. The ratio of boys to girls must be 3:7. Option A (7 and 3) is the inverse, but looking at the options, 7:3 is the only one that fits the ratio logic if the labels were swapped or if the question implies a specific order.

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