The average weight of 30 persons of group A is 3 kg more than the average weight of 25 persons of group B. The average weight of 25 persons of group B is 2.5 kg more than the average weight of 20 persons of group C. If the total weight of 30 personsof group A is 1725 kg, then what will be the average weight of the persons of group A and group C taken together (in kg)?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 55.3
Let average weight of group C be x kg
Let average weight of group B be (x + 2.5) kg
Let average weight of group A be (x + 2.5 + 3) kg
According to question:
Average weight of group A = 1725 kg/ 30
⇒ (x + 5.5) × 30 = 1725 kg
⇒ 30x + 165 = 1725
⇒ x = 1560/30 = 52 kg
Average weight of group A = 52 + 5.5 = 57.5 kg
Average weight of group C = 52 kg
Average weight of group A and C together = (57.5 × 30 + 52 × 20)/ (30 + 20)
⇒ 2765/50 = 55.3 kg